Schedule of Investments
Principal Active High Yield ETF
September 30, 2022 (unaudited)
		Principal
BONDS — 87.80%		Amount		Value
Aerospace & Defense — 1.10%
Bombardier, Inc.
7.50%, 03/15/2025 (a)	$	634,000	$	616,495
Triumph Group, Inc.
7.75%, 08/15/2025 (b)		2,431,000		1,857,790
			$	2,474,285
Airlines — 0.08%
United Airlines 2016-1 Class B Pass Through Trust
3.65%, 07/07/2027		204,042		178,826
Auto Manufacturers — 1.89%
Ford Motor Co.
3.25%, 02/12/2032		2,140,000		1,541,506
Ford Motor Credit Co. LLC
3.38%, 11/13/2025		2,276,000		2,010,862
4.39%, 01/08/2026		114,000		103,182
4.54%, 08/01/2026		672,000		598,346
			$	4,253,896
Auto Parts & Equipment — 1.49%
Tenneco, Inc.
7.88%, 01/15/2029 (a)		3,435,000		3,343,689
Banks — 1.03%
JPMorgan Chase & Co.
(6-month Secured Overnight Financing Rate + 3.13%),
4.60%, 02/01/2025 (c),(d)		2,662,000		2,318,868
Chemicals — 2.66%
Consolidated Energy Finance SA
5.63%, 10/15/2028 (a)		3,329,000		2,670,521
Kobe U.S. Midco 2, Inc.
9.25%, PIK 10.00%; 11/01/2026 (a),(e)		762,000		601,980
Olympus Water U.S. Holding Corp.
6.25%, 10/01/2029 (a),(b)		1,879,000		1,287,115
Tronox, Inc.
4.63%, 03/15/2029 (a)		1,934,000		1,431,160
			$	5,990,776
Commercial Services — 5.24%
Ahern Rentals, Inc.
7.38%, 05/15/2023 (a)		2,130,000		1,434,871
Albion Financing 1 SARL/Aggreko Holdings, Inc.
6.13%, 10/15/2026 (a)		2,430,000		2,054,394
Garda World Security Corp.
6.00%, 06/01/2029 (a)		358,000		262,483
9.50%, 11/01/2027 (a)		2,456,000		2,154,710
WASH Multifamily Acquisition, Inc.
5.75%, 04/15/2026 (a)		3,195,000		2,945,486
ZipRecruiter, Inc.
5.00%, 01/15/2030 (a)		3,632,000		2,932,840
			$	11,784,784
Construction Materials — 1.40%
SRM Escrow Issuer LLC
6.00%, 11/01/2028 (a)		3,881,000		3,154,244

See accompanying notes.

1

Schedule of Investments
Principal Active High Yield ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Diversified Financial Services — 5.86%
AerCap Holdings NV
(5-year Treasury Constant Maturity Rate + 4.54%),
5.88%, 10/10/2079 (c)	$	4,225,000	$	3,771,467
Credit Acceptance Corp.
6.63%, 03/15/2026		3,653,000		3,388,158
Global Aircraft Leasing Co. Ltd.
6.50%, PIK 7.25%; 09/15/2024 (a),(e)		3,753,570		2,824,561
OneMain Finance Corp.
4.00%, 09/15/2030		3,457,000		2,425,812
6.63%, 01/15/2028		906,000		777,348
			$	13,187,346
Electric — 4.57%
Clearway Energy Operating LLC
4.75%, 03/15/2028 (a)		3,641,000		3,241,949
GenOn Energy, Inc.
0.00%, 10/15/2020 (f),(g),(h)		3,100,000		—
NRG Energy, Inc.
3.88%, 02/15/2032 (a)		4,226,000		3,296,470
Vistra Corp.
(5-year Treasury Constant Maturity Rate + 5.74%),
7.00%, 12/15/2026 (a),(c),(d)		1,657,000		1,446,578
Vistra Operations Co. LLC
4.38%, 05/01/2029 (a)		2,748,000		2,285,594
			$	10,270,591
Electronics — 1.37%
Sensata Technologies BV
4.00%, 04/15/2029 (a)		400,000		330,996
Sensata Technologies, Inc.
3.75%, 02/15/2031 (a)		3,498,000		2,755,392
			$	3,086,388
Entertainment — 9.89%
Boyne USA, Inc.
4.75%, 05/15/2029 (a)		4,490,000		3,761,427
CCM Merger, Inc.
6.38%, 05/01/2026 (a)		3,614,000		3,297,956
CDI Escrow Issuer, Inc.
5.75%, 04/01/2030 (a)		2,740,000		2,392,883
Cinemark USA, Inc.
5.25%, 07/15/2028 (a)		3,440,000		2,645,670
International Game Technology PLC
5.25%, 01/15/2029 (a)		4,469,000		3,958,506
Lions Gate Capital Holdings LLC
5.50%, 04/15/2029 (a)		3,446,000		2,567,270
Peninsula Pacific Entertainment LLC/Peninsula Pacific Entertainment Finance,
Inc.
8.50%, 11/15/2027 (a)		3,356,000		3,611,895
			$	22,235,607
Food — 2.61%
Chobani LLC/Chobani Finance Corp., Inc.
7.50%, 04/15/2025 (a),(b)		2,910,000		2,662,126
Pilgrim's Pride Corp.
3.50%, 03/01/2032 (a)		3,729,000		2,811,182

See accompanying notes.

2

	Schedule of Investments
	Principal Active High Yield ETF
	September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Food (continued)
Pilgrim's Pride Corp. (continued)
4.25%, 04/15/2031 (a)	$	497,000	$	396,740
			$	5,870,048
Forest Products & Paper — 0.58%
Mercer International, Inc.
5.13%, 02/01/2029		1,643,000		1,309,274
Healthcare — Services — 4.12%
Acadia Healthcare Co., Inc.
5.00%, 04/15/2029 (a)		3,935,000		3,484,888
Centene Corp.
2.50%, 03/01/2031		1,749,000		1,318,364
3.38%, 02/15/2030		2,383,000		1,948,102
CHS/Community Health Systems, Inc.
6.00%, 01/15/2029 (a)		3,407,000		2,504,100
			$	9,255,454
Home Builders — 1.25%
Forestar Group, Inc.
3.85%, 05/15/2026 (a)		644,000		529,697
5.00%, 03/01/2028 (a)		2,845,000		2,282,344
			$	2,812,041
Insurance — 0.82%
Acrisure LLC/Acrisure Finance, Inc.
4.25%, 02/15/2029 (a)		439,000		344,035
7.00%, 11/15/2025 (a)		1,635,000		1,493,401
			$	1,837,436
Investment Companies — 0.85%
Compass Group Diversified Holdings LLC
5.25%, 04/15/2029 (a)		2,450,000		1,922,589
Iron & Steel — 0.60%
TMS International Corp.
6.25%, 04/15/2029 (a)		1,895,000		1,345,166
Leisure Time — 1.51%
Life Time, Inc.
5.75%, 01/15/2026 (a)		3,736,000		3,399,760
Media — 5.71%
CCO Holdings LLC/CCO Holdings Capital Corp.
4.75%, 02/01/2032 (a)		1,225,000		954,006
Directv Financing LLC/Directv Financing Co.-Obligor, Inc.
5.88%, 08/15/2027 (a)		4,275,000		3,685,520
DISH DBS Corp.
5.13%, 06/01/2029		407,000		239,113
5.25%, 12/01/2026 (a)		13,284		10,883
5.88%, 11/15/2024		1,121,000		1,000,492
7.38%, 07/01/2028		1,937,000		1,304,271
Scripps Escrow II, Inc.
5.38%, 01/15/2031 (a)		1,281,000		970,382
Sirius XM Radio, Inc.
3.13%, 09/01/2026 (a)		3,815,000		3,350,428

See accompanying notes.

3

Schedule of Investments
Principal Active High Yield ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Media (continued)
UPC Holding BV
5.50%, 01/15/2028 (a)	$	1,580,000	$	1,327,200
			$	12,842,295
Mining — 2.96%
Copper Mountain Mining Corp.
8.00%, 04/09/2026 (a)		2,087,119		1,815,793
First Quantum Minerals Ltd.
6.88%, 10/15/2027 (a)		1,655,000		1,489,500
Novelis Corp.
3.88%, 08/15/2031 (a)		2,202,000		1,642,516
Taseko Mines Ltd.
7.00%, 02/15/2026 (a)		2,155,000		1,713,225
			$	6,661,034
Oil & Gas — 6.56%
Aethon United BR LP/Aethon United Finance Corp.
8.25%, 02/15/2026 (a)		3,528,000		3,409,248
Antero Resources Corp.
7.63%, 02/01/2029 (a)		2,660,000		2,655,079
Apache Corp.
4.75%, 04/15/2043		90,000		67,082
5.10%, 09/01/2040		2,288,000		1,847,022
5.25%, 02/01/2042		192,000		156,225
Ascent Resources Utica Holdings LLC/ARU Finance Corp.
7.00%, 11/01/2026 (a)		1,216,000		1,172,388
Comstock Resources, Inc.
5.88%, 01/15/2030 (a)		1,400,000		1,219,337
MEG Energy Corp.
7.13%, 02/01/2027 (a)		2,334,000		2,369,010
Occidental Petroleum Corp.
6.13%, 01/01/2031		379,000		373,315
6.63%, 09/01/2030		1,467,000		1,489,005
			$	14,757,711
Oil & Gas Services — 0.97%
Archrock Partners LP/Archrock Partners Finance Corp.
6.25%, 04/01/2028 (a)		2,487,000		2,186,061
Packaging & Containers — 1.16%
Clydesdale Acquisition Holdings, Inc.
6.63%, 04/15/2029 (a)		397,000		361,246
8.75%, 04/15/2030 (a)		1,378,000		1,139,647
LABL, Inc.
5.88%, 11/01/2028 (a)		281,000		227,582
8.25%, 11/01/2029 (a)		1,197,000		870,059
			$	2,598,534
Pharmaceuticals — 2.37%
BellRing Brands, Inc.
7.00%, 03/15/2030 (a)		2,172,000		1,986,729
Jazz Securities DAC
4.38%, 01/15/2029 (a)		3,863,000		3,336,666
			$	5,323,395

See accompanying notes.

4

Schedule of Investments
Principal Active High Yield ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Pipelines — 8.24%
Antero Midstream Partners LP/Antero Midstream Finance Corp.
5.38%, 06/15/2029 (a)	$	2,251,000	$	1,987,408
5.75%, 03/01/2027 (a)		1,425,000		1,317,935
CNX Midstream Partners LP
4.75%, 04/15/2030 (a)		3,395,000		2,664,769
Crestwood Midstream Partners LP/Crestwood Midstream Finance Corp.
5.63%, 05/01/2027 (a)		3,701,000		3,349,405
EnLink Midstream LLC
6.50%, 09/01/2030 (a)		2,338,000		2,283,057
Hess Midstream Operations LP
4.25%, 02/15/2030 (a)		2,717,000		2,193,978
Kinetik Holdings LP
5.88%, 06/15/2030 (a)		3,718,000		3,404,420
Targa Resources Partners LP/Targa Resources Partners Finance Corp.
4.88%, 02/01/2031		1,542,000		1,326,120
			$	18,527,092
REITs — 2.43%
CBL & Associates LP
0.00%, 12/15/2026 (f),(g),(h)		6,000,000		—
HAT Holdings I LLC/HAT Holdings II LLC
3.38%, 06/15/2026 (a)		2,630,000		2,110,575
Ladder Capital Finance Holdings LLLP/Ladder Capital Finance Corp.
4.75%, 06/15/2029 (a)		4,479,000		3,353,203
			$	5,463,778
Retail — 4.99%
Bath & Body Works, Inc.
5.25%, 02/01/2028		791,000		685,388
6.63%, 10/01/2030 (a)		1,320,000		1,148,400
9.38%, 07/01/2025 (a)		384,000		397,440
BCPE Ulysses Intermediate, Inc.
7.75%, PIK 8.50%; 04/01/2027 (a),(e)		879,000		598,034
Dave & Buster's, Inc.
7.63%, 11/01/2025 (a)		2,302,000		2,267,470
Fertitta Entertainment LLC/Fertitta Entertainment Finance Co., Inc.
4.63%, 01/15/2029 (a)		1,686,000		1,395,165
6.75%, 01/15/2030 (a)		1,147,000		871,106
LSF9 Atlantis Holdings LLC/Victra Finance Corp.
7.75%, 02/15/2026 (a)		2,453,000		2,189,303
Park River Holdings, Inc.
5.63%, 02/01/2029 (a)		1,390,000		902,018
Patrick Industries, Inc.
4.75%, 05/01/2029 (a)		1,025,000		763,994
			$	11,218,318
Telecommunications — 2.29%
DKT Finance ApS
9.38%, 06/17/2023 (a)		2,701,000		2,599,712
Maxar Technologies, Inc.
7.75%, 06/15/2027 (a)		2,713,000		2,549,840
			$	5,149,552
Transportation — 1.20%
Watco Cos. LLC/Watco Finance Corp.
6.50%, 06/15/2027 (a)		2,954,000		2,688,597
TOTAL BONDS			$	197,447,435

See accompanying notes. 5

	Schedule of Investments
	Principal Active High Yield ETF
	September 30, 2022 (unaudited)
			Principal
SENIOR FLOATING RATE INTERESTS — 6.85%			Amount		Value
Airlines — 2.40%
AAdvantage Loyalty IP Ltd., 2021 Term Loan
	(3-month USD LIBOR + 4.75%),
	7.46%, 04/20/2028	$	3,355,000	$	3,244,285
United Airlines, Inc., 2021 Term Loan B
	(3-month USD LIBOR + 3.75%),
	6.53%, 04/21/2028		2,267,043		2,159,676
				$	5,403,961
Forest Products & Paper — 1.46%
Spectrum Group Buyer, Inc., 2022 Term Loan B
	(3-month Term Secured Overnight Financing Rate + 6.50%),
	9.44%, 05/19/2028		3,425,000		3,284,781
Insurance — 1.84%
Acrisure LLC, 2020 Term Loan B
	(1-month USD LIBOR + 3.50%),
	6.62%, 02/15/2027		1,645,193		1,500,547
Asurion LLC, 2021 2nd Lien Term Loan B3
	(1-month USD LIBOR + 5.25%),
	8.37%, 01/31/2028		3,505,000		2,628,750
				$	4,129,297
Lodging — 0.50%
Fertitta Entertainment LLC, 2022 Term Loan B
	(1-month Term Secured Overnight Financing Rate + 4.00%),
	7.03%, 01/27/2029		1,205,168		1,116,033
Packaging & Containers — 0.65%
Valcour Packaging LLC, 2021 1st Lien Term Loan
	(6-month USD LIBOR + 3.75%),
	5.22%, 10/04/2028		1,596,000		1,462,335
TOTAL SENIOR FLOATING RATE INTERESTS				$	15,396,407
INVESTMENT COMPANIES — 4.43%			Shares Held		Value
Money Market Funds — 4.43%
Principal Government Money Market Fund — Institutional Class 2.80% (i),(j),(k)			1,806,135	$	1,806,135
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (i)			8,157,979		8,157,979
TOTAL INVESTMENT COMPANIES				$	9,964,114
Total Investments				$	222,807,956
Other Assets and Liabilities — 0.92%					2,066,814
Total Net Assets — 100.00%				$	224,874,770
(a)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $165,411,497 or 73.56% of net assets.
(b)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $1,784,854 or
	0.79% of net assets.
(c)	Rate shown is as of period end. The rate may be a variable or floating rate or a fixed rate which may convert to a variable or
	floating rate in the future.
(d)	Perpetual security. Perpetual securities pay an indefinite stream of interest, but they may be called by the issuer at an earlier
	date. Date shown, if any, reflects the next call date or final legal maturity date. Rate shown is as of period end.
(e)	Payment in kind; the issuer has the option of paying additional securities in lieu of cash.
(f)	The value of these investments was determined using significant unobservable inputs, in good faith by the Advisor, under
	procedures established and periodically reviewed by the Board of Trustees.
(g)	Security is defaulted.
(h)	Non-income producing security.

See accompanying notes. 6

Schedule of Investments
Principal Active High Yield ETF
September 30, 2022 (unaudited)

(i)	Current yield shown is as of period end.
(j)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(k)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of these securities totaled $1,806,135 or 0.80% of net assets.

Portfolio Summary (unaudited)
Sector					Percent
Consumer, Cyclical					24.00	%
Energy					15.77	%
Consumer, Non-cyclical					14.33	%
Financial					12.83	%
Basic Materials					8.27	%
Communications					8.00	%
Industrial					6.88	%
Utilities					4.57	%
Money Market Funds					4.43	%
Other Assets and Liabilities					0.92	%
TOTAL NET ASSETS					100.00	%
			June 30, 2022		Purchases			Sales		September 30, 2022
Affiliated Securities			Value		Cost			Proceeds		Value
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	5,781,485	$	13,353,225		$	17,328,575	$	1,806,135
		$	5,781,485	$	13,353,225		$	17,328,575	$	1,806,135
								Realized Gain
					Realized			from		Change in
					Gain/(Loss) on			Capital Gain		Unrealized
			Income (a)		Investments			Distributions		Gain/(Loss)
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	—	$	—		$	—	$	—
		$	—	$	—		$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

7

Schedule of Investments
Principal Healthcare Innovators ETF
September 30, 2022 (unaudited)
COMMON STOCKS — 99.64%	Shares Held		Value
Biotechnology — 51.78%
2seventy bio, Inc. (a)	4,349	$	63,278
Absci Corp. (a)	10,707		33,513
ACADIA Pharmaceuticals, Inc. (a)	18,930		309,695
ADMA Biologics, Inc. (a)	22,645		55,027
Agenus, Inc. (a)	29,738		60,963
Akero Therapeutics, Inc. (a)	4,049		137,868
Albireo Pharma, Inc. (a)	2,239		43,347
Aldeyra Therapeutics, Inc. (a)	6,718		35,874
Allakos, Inc. (a),(b)	6,281		38,440
Allogene Therapeutics, Inc. (a)	16,508		178,286
Alnylam Pharmaceuticals, Inc. (a)	12,515		2,505,002
Altimmune, Inc. (a)	4,595		58,678
ALX Oncology Holdings, Inc. (a)	4,698		44,960
Amicus Therapeutics, Inc. (a)	32,387		338,120
AnaptysBio, Inc. (a)	3,196		81,530
Anavex Life Sciences Corp. (a)	8,808		90,899
Apellis Pharmaceuticals, Inc. (a)	11,480		784,084
Applied Molecular Transport, Inc. (a)	4,469		4,349
Arcturus Therapeutics Holdings, Inc. (a)	3,048		45,171
Arcus Biosciences, Inc. (a)	8,217		214,957
Arcutis Biotherapeutics, Inc. (a)	5,825		111,316
Arrowhead Pharmaceuticals, Inc. (a)	12,387		409,390
Atara Biotherapeutics, Inc. (a)	10,765		40,692
Atea Pharmaceuticals, Inc. (a)	9,624		54,761
Atossa Therapeutics, Inc. (a)	14,642		12,201
Avidity Biosciences, Inc. (a)	5,423		88,558
Axsome Therapeutics, Inc. (a)	4,358		194,454
Beam Therapeutics, Inc. (a)	7,948		378,643
Berkeley Lights, Inc. (a)	7,823		22,374
BioAtla, Inc. (a),(b)	4,143		31,901
BioCryst Pharmaceuticals, Inc. (a)	21,355		269,073
Biohaven Pharmaceutical Holding Co. Ltd. (a)	8,271		1,250,327
BioMarin Pharmaceutical, Inc. (a)	21,532		1,825,268
Bluebird Bio, Inc. (a)	8,107		51,317
Blueprint Medicines Corp. (a)	6,964		458,858
Bridgebio Pharma, Inc. (a)	17,070		169,676
C4 Therapeutics, Inc. (a)	5,636		49,428
Cara Therapeutics, Inc. (a)	6,181		57,854
Caribou Biosciences, Inc. (a)	6,959		73,417
Cassava Sciences, Inc. (a),(b)	4,628		193,543
CEL-SCI Corp. (a),(b)	5,003		15,459
Celldex Therapeutics, Inc. (a)	5,404		151,906
Cerevel Therapeutics Holdings, Inc. (a)	17,386		491,328
Certara, Inc. (a)	18,801		249,677
ChemoCentryx, Inc. (a)	8,099		418,394
CRISPR Therapeutics AG (a)	9,059		592,006
CTI BioPharma Corp. (a)	11,181		65,073
Cullinan Oncology, Inc. (a)	5,051		64,754
Curis, Inc. (a)	10,597		7,418
CytomX Therapeutics, Inc. (a)	7,545		10,940
Deciphera Pharmaceuticals, Inc. (a)	6,771		125,263
Denali Therapeutics, Inc. (a)	14,467		443,992
Dynavax Technologies Corp. (a)	14,446		150,816
Editas Medicine, Inc. (a)	7,924		96,990
EQRx, Inc. (a),(b)	54,367		269,117
Erasca, Inc. (a),(b)	14,022		109,372
Esperion Therapeutics, Inc. (a)	7,264		48,669
Evolus, Inc. (a)	6,426		51,729

See accompanying notes.

8

	Schedule of Investments
	Principal Healthcare Innovators ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Biotechnology (continued)
Fate Therapeutics, Inc. (a)		11,150	$	249,871
FibroGen, Inc. (a)		10,755		139,923
Forma Therapeutics Holdings, Inc. (a)		5,481		109,346
Generation Bio Co. (a)		6,591		34,998
Global Blood Therapeutics, Inc. (a)		7,495		510,409
Gossamer Bio, Inc. (a)		8,842		105,927
Guardant Health, Inc. (a)		11,944		642,946
Humanigen, Inc. (a)		7,554		1,360
Ideaya Biosciences, Inc. (a)		4,452		66,424
IGM Biosciences, Inc. (a)		3,011		68,470
ImmunityBio, Inc. (a),(b)		46,004		228,640
ImmunoGen, Inc. (a)		25,503		121,904
Immunovant, Inc. (a)		13,460		75,107
Inhibrx, Inc. (a)		4,512		80,990
Inovio Pharmaceuticals, Inc. (a)		24,330		41,969
Insmed, Inc. (a)		13,751		296,197
Intellia Therapeutics, Inc. (a)		8,781		491,385
Intercept Pharmaceuticals, Inc. (a)		3,419		47,695
Intra-Cellular Therapies, Inc. (a)		10,849		504,804
Ionis Pharmaceuticals, Inc. (a)		16,627		735,412
Iovance Biotherapeutics, Inc. (a)		18,175		174,116
iTeos Therapeutics, Inc. (a)		4,078		77,686
IVERIC bio, Inc. (a)		13,377		239,983
Karuna Therapeutics, Inc. (a)		3,507		788,830
Karyopharm Therapeutics, Inc. (a)		8,736		47,699
Keros Therapeutics, Inc. (a)		2,707		101,837
Kezar Life Sciences, Inc. (a)		5,682		48,922
Kiniksa Pharmaceuticals Ltd., Class A (a)		3,943		50,628
Kodiak Sciences, Inc. (a)		5,979		46,277
Krystal Biotech, Inc. (a)		2,914		203,106
Kymera Therapeutics, Inc. (a)		5,979		130,163
MacroGenics, Inc. (a)		7,091		24,535
MEI Pharma, Inc. (a)		15,378		5,945
Mersana Therapeutics, Inc. (a)		9,643		65,187
Mirati Therapeutics, Inc. (a)		6,527		455,846
Myriad Genetics, Inc. (a)		9,254		176,566
Nektar Therapeutics (a)		21,342		68,294
NeoGenomics, Inc. (a)		14,342		123,485
NGM Biopharmaceuticals, Inc. (a)		8,985		117,524
Novavax, Inc. (a),(b)		8,894		161,871
NRX Pharmaceuticals, Inc. (a)		6,801		5,033
Nurix Therapeutics, Inc. (a)		5,173		67,404
Nuvation Bio, Inc. (a)		25,186		56,417
Omeros Corp. (a),(b)		7,232		22,781
Precigen, Inc. (a)		23,909		50,687
Precision BioSciences, Inc. (a)		7,026		9,134
Prothena Corp. PLC (a)		5,398		327,281
Provention Bio, Inc. (a),(b)		7,328		32,976
PTC Therapeutics, Inc. (a)		8,253		414,301
Quince Therapeutics, Inc. (a),(b)		3,477		4,624
RAPT Therapeutics, Inc. (a)		3,417		82,213
Recursion Pharmaceuticals, Inc., Class A (a)		18,449		196,297
REGENXBIO, Inc. (a)		4,945		130,696
Relay Therapeutics, Inc. (a)		12,521		280,095
Replimune Group, Inc. (a)		5,459		94,277
REVOLUTION Medicines, Inc. (a)		8,578		169,158
Rigel Pharmaceuticals, Inc. (a)		19,776		23,336
Rocket Pharmaceuticals, Inc. (a)		7,460		119,062

See accompanying notes.

9

	Schedule of Investments
	Principal Healthcare Innovators ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Biotechnology (continued)
Rubius Therapeutics, Inc. (a)		10,417	$	4,519
Sage Therapeutics, Inc. (a)		6,828		267,384
Sana Biotechnology, Inc. (a),(b)		21,838		131,028
Sangamo Therapeutics, Inc. (a)		16,880		82,712
Sarepta Therapeutics, Inc. (a)		10,211		1,128,724
Scholar Rock Holding Corp. (a)		4,058		28,122
Seagen, Inc. (a)		14,184		1,940,797
Seer, Inc. (a)		6,593		51,030
Sorrento Therapeutics, Inc. (a)		42,281		66,381
SpringWorks Therapeutics, Inc. (a)		5,706		162,792
Stoke Therapeutics, Inc. (a)		4,255		54,634
Sutro Biopharma, Inc. (a)		5,363		29,765
Syndax Pharmaceuticals, Inc. (a)		6,077		146,030
TG Therapeutics, Inc. (a)		16,516		97,775
Theravance Biopharma, Inc. (a)		8,638		87,589
TransMedics Group, Inc. (a)		3,233		134,945
Travere Therapeutics, Inc. (a)		7,309		180,094
Twist Bioscience Corp. (a)		6,488		228,637
Ultragenyx Pharmaceutical, Inc. (a)		8,145		337,284
Vaxart, Inc. (a)		14,549		31,717
Veracyte, Inc. (a)		8,236		136,718
Vericel Corp. (a)		5,439		126,185
Verve Therapeutics, Inc. (a)		5,570		191,329
Viking Therapeutics, Inc. (a)		9,062		24,649
Vir Biotechnology, Inc. (a)		15,300		294,984
Xencor, Inc. (a)		6,865		178,353
Zentalis Pharmaceuticals, Inc. (a)		5,269		114,127
			$	30,236,348
Chemicals — 0.08%
Codexis, Inc. (a)		7,534		45,656
Commercial Services — 1.49%
HealthEquity, Inc. (a)		9,811		659,005
Multiplan Corp. (a)		73,852		211,217
			$	870,222
Electronics — 0.02%
Standard BioTools, Inc. (a)		8,927		9,820
Engineering & Construction — 0.10%
908 Devices, Inc. (a)		3,612		59,417
Healthcare — Products — 18.07%
10X Genomics, Inc., Class A (a)		10,959		312,112
Adaptive Biotechnologies Corp. (a)		16,373		116,576
Alphatec Holdings, Inc. (a)		11,539		100,851
AngioDynamics, Inc. (a)		4,477		91,599
Artivion, Inc. (a)		4,638		64,190
AtriCure, Inc. (a)		5,323		208,129
Avanos Medical, Inc. (a)		5,472		119,180
Axonics, Inc. (a)		5,431		382,560
BioLife Solutions, Inc. (a)		4,815		109,541
Bionano Genomics, Inc. (a),(b)		33,493		61,292
Biora Therapeutics, Inc. (a)		19,170		9,296
Butterfly Network, Inc. (a),(b)		19,860		93,342
Cardiovascular Systems, Inc. (a)		4,692		65,031
CareDx, Inc. (a)		6,131		104,350
Castle Biosciences, Inc. (a)		2,938		76,623

See accompanying notes.

10

	Schedule of Investments
	Principal Healthcare Innovators ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Healthcare — Products (continued)
Cerus Corp. (a)		20,090	$	72,324
Cue Health, Inc. (a),(b)		16,927		50,950
Cutera, Inc. (a)		2,089		95,258
DermTech, Inc. (a),(b)		3,452		13,670
Eargo, Inc. (a)		4,545		4,772
Exact Sciences Corp. (a)		20,390		662,471
Glaukos Corp. (a)		5,440		289,626
Inari Medical, Inc. (a)		5,947		431,990
Inogen, Inc. (a)		2,628		63,808
Inspire Medical Systems, Inc. (a)		3,232		573,260
iRhythm Technologies, Inc. (a)		3,470		434,722
Lantheus Holdings, Inc. (a)		7,997		562,429
LivaNova PLC (a)		6,995		355,136
MiMedx Group, Inc. (a)		12,993		37,290
NanoString Technologies, Inc. (a)		5,278		67,400
Natera, Inc. (a)		11,232		492,186
Nevro Corp. (a)		4,054		188,916
Novocure Ltd. (a)		12,235		929,615
NuVasive, Inc. (a)		5,987		262,291
OraSure Technologies, Inc. (a)		8,361		31,688
OrthoPediatrics Corp. (a)		2,283		105,338
Pacific Biosciences of California, Inc. (a)		25,580		148,492
Penumbra, Inc. (a)		4,414		836,894
PROCEPT BioRobotics Corp. (a)		5,030		208,544
Pulmonx Corp. (a)		4,280		71,305
Quanterix Corp. (a)		4,261		46,956
Quantum-Si, Inc. (a),(b)		13,586		37,362
Shockwave Medical, Inc. (a)		4,183		1,163,167
SI-BONE, Inc. (a)		3,912		68,304
Silk Road Medical, Inc. (a)		4,049		182,205
SmileDirectClub, Inc. (a),(b)		13,918		12,601
SomaLogic, Inc. (a)		20,952		60,761
ViewRay, Inc. (a)		20,747		75,519
			$	10,551,922
Healthcare — Services — 7.91%
23andMe Holding Co., Class A (a),(b)		24,420		69,841
Accolade, Inc. (a)		7,743		88,425
agilon health, Inc. (a)		47,021		1,101,232
American Well Corp., Class A (a)		26,641		95,641
ATI Physical Therapy, Inc. (a),(b)		22,828		22,828
Bright Health Group, Inc. (a),(b)		72,714		76,350
Brookdale Senior Living, Inc. (a)		21,461		91,638
Cano Health, Inc. (a)		23,140		200,624
Clover Health Investments Corp. (a)		43,777		74,421
Ginkgo Bioworks Holdings, Inc. (a),(b)		139,838		436,295
Inotiv, Inc. (a)		2,944		49,606
Invitae Corp. (a),(b)		26,408		64,964
LifeStance Health Group, Inc. (a),(b)		43,284		286,540
ModivCare, Inc. (a)		2,249		224,180
Oak Street Health, Inc. (a)		28,277		693,352
OPKO Health, Inc. (a)		78,809		148,949
Personalis, Inc. (a)		5,198		15,438
RadNet, Inc. (a)		6,497		132,214
Sema4 Holdings Corp. (a)		28,329		24,859
Surgery Partners, Inc. (a)		10,493		245,536
Teladoc Health, Inc. (a)		18,811		476,859
			$	4,619,792

See accompanying notes.

11

	Schedule of Investments
	Principal Healthcare Innovators ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Pharmaceuticals — 16.30%
Aclaris Therapeutics, Inc. (a)		7,086	$	111,534
Aerie Pharmaceuticals, Inc. (a)		5,596		84,668
Agios Pharmaceuticals, Inc. (a)		6,318		178,673
Akebia Therapeutics, Inc. (a)		20,233		6,398
Alector, Inc. (a)		9,487		89,747
Alkermes PLC (a)		19,016		424,627
Amneal Pharmaceuticals, Inc. (a)		17,280		34,906
Arvinas, Inc. (a)		6,135		272,946
Bioxcel Therapeutics, Inc. (a),(b)		3,235		38,238
Chimerix, Inc. (a)		10,045		19,387
Clovis Oncology, Inc. (a),(b)		16,450		19,576
Coherus Biosciences, Inc. (a)		8,936		85,875
Collegium Pharmaceutical, Inc. (a)		3,859		61,821
Cytokinetics, Inc. (a)		9,982		483,628
Eagle Pharmaceuticals, Inc. (a)		1,493		39,445
Elanco Animal Health, Inc. (a)		55,384		687,316
Enanta Pharmaceuticals, Inc. (a)		2,375		123,191
Fulcrum Therapeutics, Inc. (a)		4,689		37,934
G1 Therapeutics, Inc. (a)		4,937		61,663
GoodRx Holdings, Inc., Class A (a)		9,332		43,580
Gritstone bio, Inc. (a)		7,862		20,205
Harmony Biosciences Holdings, Inc. (a)		6,807		301,482
Heron Therapeutics, Inc. (a)		11,811		49,842
Heska Corp. (a)		1,248		91,004
Jazz Pharmaceuticals PLC (a)		7,198		959,421
Kura Oncology, Inc. (a)		7,702		105,209
Lyell Immunopharma, Inc. (a)		27,809		203,840
Madrigal Pharmaceuticals, Inc. (a)		1,978		128,550
MannKind Corp. (a)		29,119		89,978
Marinus Pharmaceuticals, Inc. (a),(b)		4,251		28,269
Morphic Holding, Inc. (a)		4,290		121,407
Neurocrine Biosciences, Inc. (a)		11,157		1,184,985
Ocugen, Inc. (a),(b)		23,069		41,063
Ocular Therapeutix, Inc. (a)		8,876		36,835
ORIC Pharmaceuticals, Inc. (a)		4,554		14,573
Perrigo Co. PLC		15,708		560,147
PetIQ, Inc. (a)		3,368		23,239
PMV Pharmaceuticals, Inc. (a)		5,247		62,439
Prometheus Biosciences, Inc. (a)		4,502		265,663
Protagonist Therapeutics, Inc. (a)		5,598		47,191
Reata Pharmaceuticals, Inc., Class A (a)		3,640		91,473
Relmada Therapeutics, Inc. (a)		3,205		118,649
Revance Therapeutics, Inc. (a)		8,262		223,074
Rhythm Pharmaceuticals, Inc. (a)		5,812		142,394
Senseonics Holdings, Inc. (a),(b)		53,563		70,703
Seres Therapeutics, Inc. (a)		10,621		68,187
uniQure NV (a)		5,372		100,779
Vaxcyte, Inc. (a)		6,512		156,288
Viatris, Inc.		141,565		1,206,134
Xeris Biopharma Holdings, Inc. (a),(b)		15,625		24,375
Y-mAbs Therapeutics, Inc. (a)		5,047		72,778
			$	9,515,329
Retail — 0.25%
Warby Parker, Inc., Class A (a)		11,018		146,980
Software — 3.64%
1Life Healthcare, Inc. (a)		22,216		381,004
Alignment Healthcare, Inc. (a)		21,633		256,135

See accompanying notes.

12

			Schedule of Investments
			Principal Healthcare Innovators ETF
			September 30, 2022 (unaudited)
COMMON STOCKS (continued)								Shares Held		Value
Software (continued)
Definitive Healthcare Corp. (a)								11,262	$	175,012
Evolent Health, Inc., Class A (a)								10,503		377,373
Health Catalyst, Inc. (a)								6,169		59,839
Hims & Hers Health, Inc. (a)								22,747		126,928
Outset Medical, Inc. (a)								5,482		87,328
Phreesia, Inc. (a)								5,925		150,969
Privia Health Group, Inc. (a)								12,315		419,449
Sharecare, Inc. (a)								39,208		74,495
Tabula Rasa HealthCare, Inc. (a)								2,975		14,280
									$	2,122,812
TOTAL COMMON STOCKS									$	58,178,298
INVESTMENT COMPANIES — 3.37%								Shares Held		Value
Money Market Funds — 3.37%
Principal Government Money Market Fund — Institutional Class 2.80% (c),(d),(e)								1,740,395	$	1,740,395
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (e)								228,287		228,287
TOTAL INVESTMENT COMPANIES									$	1,968,682
Total Investments									$	60,146,980
Other Assets and Liabilities — (3.01)%										(1,755,716	)
Total Net Assets — 100.00%									$	58,391,264
(a)	Non-income producing security.
(b)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $1,621,565 or
	2.78% of net assets.
(c)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(d)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $1,740,395 or 2.98% of net assets.
(e)	Current yield shown is as of period end.
	Portfolio Summary (unaudited)
Sector					Percent
Consumer, Non-cyclical					95.55	%
Technology					3.64	%
Money Market Funds					3.37	%
Consumer, Cyclical					0.25	%
Industrial					0.12	%
Basic Materials					0.08	%
Other Assets and Liabilities					(3.01	)%
TOTAL NET ASSETS					100.00	%
		June 30, 2022			Purchases			Sales	September 30, 2022
Affiliated Securities			Value		Cost			Proceeds		Value
Principal Government Money
Market Fund — Institutional Class
2.80%		$	1,097,187	$	7,155,292		$	6,512,084	$	1,740,395
		$	1,097,187	$	7,155,292		$	6,512,084	$	1,740,395

See accompanying notes. 13

			Schedule of Investments
			Principal Healthcare Innovators ETF
			September 30, 2022 (unaudited)
						Realized Gain
					Realized		from		Change in
				Gain/(Loss) on		Capital Gain			Unrealized
			Income (a)	Investments		Distributions			Gain/(Loss)
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	—	$	—	$	—	$	—
		$	—	$	—	$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

14

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS — 98.46%	Shares Held		Value
Advertising — 0.29%
Dentsu Group, Inc.	400	$	11,359
Hakuhodo DY Holdings, Inc.	1,100		7,737
Publicis Groupe SA	125		5,991
WPP PLC	677		5,669
		$	30,756
Aerospace & Defense — 0.95%
Airbus SE	177		15,420
BAE Systems PLC	3,826		33,739
Dassault Aviation SA	68		7,797
Elbit Systems Ltd.	26		4,936
MTU Aero Engines AG	35		5,291
Rheinmetall AG	68		10,543
Safran SA	111		10,227
Thales SA	129		14,286
		$	102,239
Agriculture — 1.29%
British American Tobacco PLC	1,966		70,826
Imperial Brands PLC	1,255		25,994
Japan Tobacco, Inc.	1,500		24,605
Swedish Match AB	1,723		17,078
		$	138,503
Airlines — 0.21%
Air Canada (a)	300		3,605
Deutsche Lufthansa AG (a)	728		4,222
Qantas Airways Ltd. (a)	1,226		3,937
Singapore Airlines Ltd. (a)	2,900		10,298
		$	22,062
Apparel — 1.60%
Burberry Group PLC	287		5,794
Gildan Activewear, Inc.	333		9,414
Hermes International	11		13,120
Kering SA	24		10,785
LVMH Moet Hennessy Louis Vuitton SE	215		128,618
Puma SE	88		4,137
		$	171,868
Auto Manufacturers — 1.79%
Bayerische Motoren Werke AG	127		8,712
Ferrari NV	107		20,103
Honda Motor Co. Ltd.	1,300		28,177
Isuzu Motors Ltd.	1,000		11,034
Renault SA (a)	165		4,523
Stellantis NV	785		9,441
Toyota Motor Corp.	8,200		106,289
Volvo AB, Class A	278		4,128
		$	192,407
Auto Parts & Equipment — 0.13%
NGK Insulators Ltd.	800		9,950
Valeo SA	253		3,875
		$	13,825

See accompanying notes.

15

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Banks — 9.05%
ABN AMRO Bank NV (b)	460	$	4,160
Australia & New Zealand Banking Group Ltd.	2,161		31,516
Bank Hapoalim BM	1,371		11,629
Bank Leumi Le-Israel BM	2,419		20,770
Bank of Montreal	644		56,444
Bank of Nova Scotia	803		38,192
BOC Hong Kong Holdings Ltd.	5,000		16,657
CaixaBank SA	2,111		6,850
Canadian Imperial Bank of Commerce	384		16,807
Chiba Bank Ltd.	1,800		9,688
Commerzbank AG (a)	729		5,246
Commonwealth Bank of Australia	732		42,468
Concordia Financial Group Ltd.	3,200		9,883
Danske Bank A/S	435		5,438
DBS Group Holdings Ltd.	1,300		30,222
DNB Bank ASA	949		15,065
FinecoBank Banca Fineco SpA	423		5,279
Hang Seng Bank Ltd.	996		15,125
HSBC Holdings PLC	15,595		81,369
Israel Discount Bank Ltd., Class A	3,100		15,699
Lloyds Banking Group PLC	23,102		10,676
Macquarie Group Ltd.	268		26,184
Mediobanca Banca di Credito Finanziario SpA	737		5,822
Mitsubishi UFJ Financial Group, Inc.	9,200		41,414
Mizrahi Tefahot Bank Ltd.	436		15,343
Mizuho Financial Group, Inc.	2,600		28,069
National Australia Bank Ltd.	2,162		39,842
National Bank of Canada	300		18,803
NatWest Group PLC	2,469		6,228
Oversea-Chinese Banking Corp. Ltd.	2,800		23,063
Royal Bank of Canada	957		86,164
Shizuoka Bank Ltd. (a)	1,700		10,442
Societe Generale SA	344		6,883
Standard Chartered PLC	2,264		14,328
Sumitomo Mitsui Financial Group, Inc.	1,000		27,803
Svenska Handelsbanken AB, Class A	1,689		13,944
Swedbank AB, Class A	609		8,059
Toronto-Dominion Bank	1,230		75,437
UBS Group AG	1,046		15,345
UniCredit SpA	837		8,579
United Overseas Bank Ltd.	1,100		20,036
Westpac Banking Corp.	2,523		33,310
		$	974,281
Beverages — 2.57%
Anheuser-Busch InBev SA	640		29,320
Budweiser Brewing Co. APAC Ltd. (b)	1,600		4,189
Carlsberg AS, Class B	68		8,011
Coca-Cola Europacific Partners PLC	420		17,901
Coca-Cola HBC AG	497		10,510
Davide Campari-Milano NV	524		4,680
Diageo PLC	2,065		87,558
Endeavour Group Ltd.	2,496		11,176
Heineken Holding NV	174		12,022
Heineken NV	330		29,062
JDE Peet's NV	479		14,055
Pernod Ricard SA	158		29,243
Remy Cointreau SA	52		8,710

See accompanying notes.

16

	Schedule of Investments
	Principal International Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Beverages (continued)
Treasury Wine Estates Ltd.	1,297	$	10,428
		$	276,865
Biotechnology — 0.75%
Argenx SE (a)	21		7,584
Bachem Holding AG, Class B	74		4,710
CSL Ltd.	305		55,606
Genmab A/S (a)	24		7,785
Swedish Orphan Biovitrum AB (a)	269		5,226
		$	80,911
Chemicals — 2.50%
Air Liquide SA	200		23,043
Arkema SA	62		4,562
BASF SE	302		11,721
Brenntag SE	94		5,747
Clariant AG	274		4,415
Croda International PLC	79		5,686
EMS-Chemie Holding AG	9		5,733
Givaudan SA	8		24,348
ICL Group Ltd.	1,211		9,780
Mitsubishi Chemical Group Corp.	2,500		11,428
Mitsui Chemicals, Inc.	500		9,739
Nippon Sanso Holdings Corp.	600		9,456
Nissan Chemical Corp.	200		8,913
Nitto Denko Corp.	200		10,820
Nutrien Ltd.	355		29,606
OCI NV	237		8,724
Shin-Etsu Chemical Co. Ltd.	300		29,703
Solvay SA	63		4,917
Sumitomo Chemical Co. Ltd.	3,300		11,332
Symrise AG	152		14,964
Tosoh Corp.	900		10,012
Umicore SA	170		5,020
Yara International ASA	258		9,082
		$	268,751
Commercial Services — 3.21%
Adyen NV (a),(b)	8		10,207
Amadeus IT Group SA (a)	400		18,782
Ashtead Group PLC	177		8,075
Atlantia SpA	631		13,982
Brambles Ltd.	1,738		12,685
Bureau Veritas SA	490		11,036
Dai Nippon Printing Co. Ltd.	600		12,022
Edenred	443		20,562
Experian PLC	779		23,145
GMO Payment Gateway, Inc.	100		6,875
IDP Education Ltd.	232		3,928
Intertek Group PLC	268		11,093
Nuvei Corp. (a),(b)	150		4,054
Persol Holdings Co. Ltd.	600		11,090
Recruit Holdings Co. Ltd.	1,100		31,625
RELX PLC	1,992		48,976
Rentokil Initial PLC	2,345		12,502
Ritchie Bros Auctioneers, Inc.	174		10,872
Secom Co. Ltd.	300		17,155
Securitas AB, Class B	666		4,657

See accompanying notes.

17

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Commercial Services (continued)
Securitas AB — Rights	3,464	$	1,445
SGS SA	7		15,075
TOPPAN, Inc.	700		10,418
Transurban Group	2,603		20,546
Worldline SA (a),(b)	133		5,302
		$	346,109
Computers — 1.45%
Bechtle AG	105		3,821
Capgemini SE	61		9,894
CGI, Inc. (a)	322		24,241
Check Point Software Technologies Ltd. (a)	180		20,164
Computershare Ltd.	760		12,037
Itochu Techno-Solutions Corp.	400		9,369
NEC Corp.	400		12,782
Nomura Research Institute Ltd.	600		14,717
NTT Data Corp.	1,100		14,182
Otsuka Corp.	300		9,379
SCSK Corp.	700		10,592
Teleperformance	59		15,086
		$	156,264
Construction Materials — 1.13%
AGC, Inc.	400		12,409
Cie de Saint-Gobain	207		7,516
Daikin Industries Ltd.	200		30,809
Geberit AG	37		16,031
Holcim AG	471		19,562
Investment AB Latour, Class B	236		3,947
James Hardie Industries PLC	274		5,405
Kingspan Group PLC	103		4,678
Nibe Industrier AB, Class B	717		6,467
Sika AG	51		10,374
Xinyi Glass Holdings Ltd.	3,000		4,365
		$	121,563
Distribution/Wholesale — 1.78%
Bunzl PLC	651		20,062
Ferguson PLC	191		20,055
IMCD NV	43		5,167
ITOCHU Corp.	1,200		29,028
Marubeni Corp.	2,000		17,522
Mitsubishi Corp.	1,000		27,416
Mitsui & Co. Ltd.	1,400		29,880
Sumitomo Corp.	1,500		18,681
Toromont Industries Ltd.	156		10,860
Toyota Tsusho Corp.	400		12,382
		$	191,053
Diversified Financial Services — 2.27%
AerCap Holdings NV (a)	111		4,699
Amundi SA (b)	91		3,831
ASX Ltd.	284		13,036
Deutsche Boerse AG	214		35,287
Euronext NV (b)	163		10,400
Futu Holdings Ltd., ADR (a)	105		3,915
Hong Kong Exchanges & Clearing Ltd.	900		30,911
IGM Financial, Inc.	376		9,369
Japan Exchange Group, Inc.	900		12,142

See accompanying notes.

18

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Diversified Financial Services (continued)
Julius Baer Group Ltd.	130	$	5,731
London Stock Exchange Group PLC	390		33,216
Mitsubishi HC Capital, Inc.	2,200		9,455
ORIX Corp.	1,300		18,221
Partners Group Holding AG	9		7,339
SBI Holdings, Inc.	600		10,762
Schroders PLC	894		3,886
Singapore Exchange Ltd.	2,400		15,808
TMX Group Ltd.	171		15,729
		$	243,737
Electric — 3.80%
Algonquin Power & Utilities Corp.	1,056		11,536
Brookfield Renewable Corp., Class A	402		13,137
Canadian Utilities Ltd., Class A	340		8,844
CLP Holdings Ltd.	1,881		14,222
E.ON SE	1,232		9,534
EDP - Energias de Portugal SA	3,057		13,302
EDP Renovaveis SA	211		4,351
Electricite de France SA	452		5,267
Elia Group SA	79		9,322
Emera, Inc.	336		13,595
Endesa SA	907		13,707
Enel SpA	3,306		13,686
Engie SA	2,315		26,867
Fortis, Inc.	471		17,894
HK Electric Investments & HK Electric Investments Ltd.	12,000		8,408
Hydro One Ltd. (b)	726		17,754
Iberdrola SA	5,712		53,640
Mercury NZ Ltd.	2,553		8,144
Meridian Energy Ltd.	3,288		8,833
National Grid PLC	3,805		39,553
Northland Power, Inc.	572		16,750
Origin Energy Ltd.	1,403		4,640
Power Assets Holdings Ltd.	2,500		12,548
Red Electrica Corp. SA	699		10,762
RWE AG	243		9,000
SSE PLC	1,002		17,089
Terna - Rete Elettrica Nazionale	2,758		16,894
Verbund AG	111		9,513
		$	408,792
Electrical Components & Equipment — 0.54%
ABB Ltd.	1,193		31,194
Legrand SA	258		16,855
Prysmian SpA	345		10,015
		$	58,064
Electronics — 1.46%
Assa Abloy AB, Class B	396		7,483
Halma PLC	251		5,731
Hirose Electric Co. Ltd.	100		13,114
Hoya Corp.	300		28,771
Ibiden Co. Ltd.	400		10,944
MINEBEA MITSUMI, Inc.	700		10,345
Murata Manufacturing Co. Ltd.	600		27,494
Nidec Corp.	300		16,852

See accompanying notes.

19

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Electronics (continued)
Shimadzu Corp.	467	$	12,245
TDK Corp.	500		15,391
Venture Corp. Ltd.	791		9,049
		$	157,419
Energy — Alternate Sources — 0.05%
Siemens Gamesa Renewable Energy SA (a)	314		5,516
Engineering & Construction — 1.93%
Acciona SA	52		9,204
ACS Actividades de Construccion y Servicios SA	486		11,017
Aena SME SA (a),(b)	110		11,524
Aeroports de Paris (a)	39		4,548
Auckland International Airport Ltd. (a)	2,430		9,792
Bouygues SA	243		6,394
CK Infrastructure Holdings Ltd.	2,000		10,204
Eiffage SA	199		16,094
Ferrovial SA	839		19,233
Infrastrutture Wireless Italiane SpA (b)	1,006		8,844
Keppel Corp. Ltd.	2,300		11,130
Lendlease Corp. Ltd.	1,600		9,129
Singapore Technologies Engineering Ltd.	4,100		10,220
Taisei Corp.	400		11,110
Vinci SA	541		44,097
WSP Global, Inc.	141		15,528
		$	208,068
Entertainment — 0.47%
Aristocrat Leisure Ltd.	668		14,066
Entain PLC	401		4,862
Evolution AB (b)	88		7,032
Genting Singapore Ltd.	17,200		9,401
La Francaise des Jeux SAEM (b)	321		9,586
Lottery Corp. Ltd. (a)	2,286		6,112
		$	51,059
Food — 5.58%
Barry Callebaut AG	6		11,365
Carrefour SA	862		12,009
Chocoladefabriken Lindt & Spruengli AG	1		9,689
Coles Group Ltd.	1,485		15,607
Danone SA	505		24,039
Empire Co. Ltd., Class A	541		13,457
George Weston Ltd.	164		17,171
J Sainsbury PLC	4,537		8,830
Jeronimo Martins SGPS SA	770		14,376
Kerry Group PLC, Class A	169		15,105
Kesko Oyj, Class B	243		4,559
Koninklijke Ahold Delhaize NV	866		22,181
Loblaw Cos. Ltd.	271		21,459
MEIJI Holdings Co. Ltd.	300		13,328
Metro, Inc.	412		20,631
Mowi ASA	658		8,370
Nestle SA	2,179		236,472
Nisshin Seifun Group, Inc.	900		9,129
Orkla ASA	2,033		14,787
Salmar ASA	145		4,890
Saputo, Inc.	479		11,419

See accompanying notes.

20

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Food (continued)
Seven & i Holdings Co. Ltd.	600	$	24,070
Tesco PLC	7,220		16,671
WH Group Ltd. (b)	23,500		14,819
Wilmar International Ltd.	5,600		14,972
Woolworths Group Ltd.	992		21,542
		$	600,947
Food Service — 0.36%
Compass Group PLC	1,366		27,530
Sodexo SA	150		11,343
		$	38,873
Forest Products & Paper — 0.47%
Holmen AB, Class B	104		3,978
Mondi PLC	337		5,245
Oji Holdings Corp.	2,700		10,037
Smurfit Kappa Group PLC	173		4,973
UPM-Kymmene Oyj	540		17,242
West Fraser Timber Co. Ltd.	127		9,188
		$	50,663
Gas — 0.77%
AltaGas Ltd.	542		10,378
Enagas SA	609		9,454
Hong Kong & China Gas Co. Ltd.	8,250		7,273
Naturgy Energy Group SA	583		13,559
Osaka Gas Co. Ltd.	800		12,083
Snam SpA	4,060		16,497
Tokyo Gas Co. Ltd.	800		13,548
		$	82,792
Hand/Machine Tools — 0.46%
Disco Corp.	100		22,110
Fuji Electric Co. Ltd.	300		10,965
Schindler Holding AG	38		5,956
Schindler Holding AG	34		5,169
Techtronic Industries Co. Ltd.	500		4,831
		$	49,031
Healthcare — Products — 1.29%
Alcon, Inc.	224		13,199
Carl Zeiss Meditec AG	41		4,318
Cochlear Ltd.	140		17,421
Coloplast A/S, Class B	60		6,136
Demant A/S (a)	150		3,736
DiaSorin SpA	35		3,938
EssilorLuxottica SA	121		16,643
Fisher & Paykel Healthcare Corp. Ltd.	448		4,638
Lifco AB, Class B	294		4,138
Olympus Corp.	1,000		19,198
QIAGEN NV (a)	308		12,974
Sartorius Stedim Biotech	18		5,594
Siemens Healthineers AG (b)	149		6,466
Smith & Nephew PLC	628		7,366
Sonova Holding AG	29		6,466
Straumann Holding AG	65		6,050
		$	138,281

See accompanying notes.

21

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Healthcare — Services — 0.52%
BioMerieux	51	$	4,069
Eurofins Scientific SE	88		5,271
Fresenius SE & Co. KGaA	314		6,755
Lonza Group AG	23		11,336
Medibank Pvt Ltd.	4,980		11,053
Ramsay Health Care Ltd.	133		4,873
Sonic Healthcare Ltd.	645		12,616
		$	55,973
Holding Companies — Diversified — 0.39%
CK Hutchison Holdings Ltd.	3,000		16,587
Jardine Matheson Holdings Ltd.	283		14,331
Swire Pacific Ltd., Class A	1,500		11,226
		$	42,144
Home Builders — 0.46%
Daiwa House Industry Co. Ltd.	800		16,270
Iida Group Holdings Co. Ltd.	600		8,138
Open House Group Co. Ltd.	300		10,146
Sekisui House Ltd.	900		14,931
		$	49,485
Home Furnishings — 0.67%
SEB SA	133		8,433
Sony Group Corp.	1,000		64,161
		$	72,594
Household Products — 1.36%
Beiersdorf AG	131		12,961
Essity AB, Class B	403		8,018
L'Oreal SA	156		50,491
Unilever PLC	1,684		74,628
		$	146,098
Household Products/Wares — 0.55%
Henkel AG & Co. KGaA	194		11,085
Reckitt Benckiser Group PLC	722		48,175
		$	59,260
Insurance — 5.36%
Aegon NV	1,239		4,981
Ageas SA	126		4,623
AIA Group Ltd.	9,400		78,377
Allianz SE	153		24,262
Assicurazioni Generali SpA	650		8,931
Aviva PLC	1,418		6,146
AXA SA	1,896		41,763
Baloise Holding AG	84		10,786
Fairfax Financial Holdings Ltd.	30		13,702
Gjensidige Forsikring ASA	300		5,152
Great-West Lifeco, Inc.	282		6,088
iA Financial Corp., Inc.	304		15,447
Insurance Australia Group Ltd.	4,062		11,952
Intact Financial Corp.	215		30,427
M&G PLC	2,268		4,218
Manulife Financial Corp.	2,204		34,591
Muenchener Rueckversicherungs-Gesellschaft AG in Muenchen	107		25,954

See accompanying notes.

22

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Insurance (continued)
Phoenix Group Holdings PLC	1,589	$	9,346
Power Corp. of Canada	621		13,995
QBE Insurance Group Ltd.	2,673		19,714
Sampo Oyj, Class A	646		27,705
Sompo Holdings, Inc.	400		15,925
Sun Life Financial, Inc.	532		21,155
Suncorp Group Ltd.	1,916		12,292
Swiss Life Holding AG	33		14,666
Swiss Re AG	262		19,426
Tokio Marine Holdings, Inc.	1,500		26,584
Tryg A/S	548		11,333
Zurich Insurance Group AG	144		57,647
		$	577,188
Internet — 0.73%
Adevinta ASA (a)	555		3,313
Auto Trader Group PLC (b)	1,485		8,539
CyberAgent, Inc.	1,200		10,099
MonotaRO Co. Ltd.	700		10,747
Prosus NV	256		13,541
Trend Micro, Inc.	300		16,210
United Internet AG	426		8,041
ZOZO, Inc.	400		7,998
		$	78,488
Investment Companies — 0.16%
EXOR NV (a)	77		4,941
Groupe Bruxelles Lambert NV	89		6,270
Washington H Soul Pattinson & Co. Ltd.	322		5,518
		$	16,729
Iron & Steel — 0.55%
ArcelorMittal SA	289		5,853
BlueScope Steel Ltd.	455		4,421
Fortescue Metals Group Ltd.	1,423		15,310
JFE Holdings, Inc.	1,000		9,266
Mineral Resources Ltd.	126		5,299
Nippon Steel Corp.	1,100		15,250
voestalpine AG	218		3,741
		$	59,140
Leisure Products & Services — 0.04%
BRP, Inc.	63		3,881
Leisure Time — 0.25%
Shimano, Inc.	100		15,712
Yamaha Motor Co. Ltd.	600		11,222
		$	26,934
Lodging — 0.27%
Accor SA (a)	184		3,897
City Developments Ltd.	1,600		8,467
Galaxy Entertainment Group Ltd.	1,000		5,911
InterContinental Hotels Group PLC	108		5,268
Sands China Ltd. (a)	2,000		5,019
		$	28,562

See accompanying notes.

23

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Machinery — Construction & Mining — 0.78%
Epiroc AB, Class A	399	$	5,758
Epiroc AB, Class B	367		4,663
Hitachi Construction Machinery Co. Ltd.	400		7,396
Hitachi Ltd.	700		29,571
Komatsu Ltd.	1,100		19,844
Mitsubishi Heavy Industries Ltd.	500		16,603
		$	83,835
Machinery — Diversified — 1.32%
Atlas Copco AB, Class A	943		8,905
Atlas Copco AB, Class B	737		6,193
CNH Industrial NV	552		6,292
GEA Group AG	150		4,901
Husqvarna AB, Class B	715		4,001
Keyence Corp.	200		66,192
SMC Corp.	100		40,227
Spirax-Sarco Engineering PLC	49		5,690
		$	142,401
Media — 0.88%
Bollore SE	1,246		5,766
Informa PLC	944		5,473
Pearson PLC	500		4,839
Quebecor, Inc., Class B	719		13,257
Shaw Communications, Inc., Class B	576		14,006
Thomson Reuters Corp.	90		9,239
Vivendi SE	1,365		10,665
Wolters Kluwer NV	319		31,239
		$	94,484
Metal Fabrication & Hardware — 0.14%
Tenaris SA	754		9,802
VAT Group AG (b)	23		4,751
		$	14,553
Mining — 2.92%
Anglo American PLC	821		25,076
BHP Group Ltd.	3,890		95,847
Boliden AB	366		11,429
Cameco Corp.	255		6,767
First Quantum Minerals Ltd.	721		12,240
Franco-Nevada Corp.	167		19,948
Glencore PLC	5,908		31,542
Lundin Mining Corp.	905		4,573
Norsk Hydro ASA	1,757		9,495
Rio Tinto Ltd.	291		17,383
Rio Tinto PLC	656		35,861
South32 Ltd.	4,902		11,382
Sumitomo Metal Mining Co. Ltd.	400		11,497
Teck Resources Ltd., Class B	470		14,294
Wheaton Precious Metals Corp.	222		7,189
		$	314,523
Miscellaneous Manufacturers — 0.23%
Indutrade AB	266		4,372
Orica Ltd.	1,093		9,243

See accompanying notes.

24

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Miscellaneous Manufacturers (continued)
Smiths Group PLC	683	$	11,515
		$	25,130
Office & Business Equipment — 0.30%
FUJIFILM Holdings Corp.	500		22,832
Seiko Epson Corp.	700		9,528
		$	32,360
Oil & Gas — 5.56%
Aker BP ASA	372		10,680
Ampol Ltd.	768		14,124
ARC Resources Ltd.	800		9,608
BP PLC	14,785		71,497
Canadian Natural Resources Ltd.	676		31,467
Cenovus Energy, Inc.	1,037		15,930
DCC PLC	117		6,126
ENEOS Holdings, Inc.	4,600		14,782
Eni SpA	918		9,816
Equinor ASA	668		21,969
Galp Energia SGPS SA	471		4,535
Idemitsu Kosan Co. Ltd.	500		10,831
Imperial Oil Ltd.	273		11,820
Inpex Corp.	1,500		14,085
Neste Oyj	183		8,035
OMV AG	132		4,834
Parkland Corp.	379		8,121
Repsol SA	1,301		15,052
Santos Ltd.	2,871		13,020
Shell PLC	5,768		144,680
Suncor Energy, Inc.	941		26,499
TotalEnergies SE	1,926		91,123
Tourmaline Oil Corp.	281		14,604
Woodside Energy Group Ltd.	1,221		24,727
		$	597,965
Packaging & Containers — 0.22%
CCL Industries, Inc., Class B	369		17,887
SIG Group AG	274		5,604
		$	23,491
Pharmaceuticals — 8.45%
Amplifon SpA	176		4,640
Astellas Pharma, Inc.	200		2,649
AstraZeneca PLC	1,202		133,458
Bayer AG	598		27,788
Chugai Pharmaceutical Co. Ltd.	900		22,548
Daiichi Sankyo Co. Ltd.	1,400		39,099
GSK PLC	3,924		57,212
Hikma Pharmaceuticals PLC	292		4,445
Ipsen SA	94		8,743
Merck KGaA	53		8,664
Novartis AG	1,813		138,782
Novo Nordisk A/S, Class B	1,285		128,966
Ono Pharmaceutical Co. Ltd.	600		14,016
Orion Oyj, Class B	244		10,302
Recordati Industria Chimica e Farmaceutica SpA	260		9,604
Roche Holding AG	50		19,651
Roche Holding AG	545		178,656

See accompanying notes.

25

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Pharmaceuticals (continued)
Sanofi	726	$	55,783
Takeda Pharmaceutical Co. Ltd.	1,200		31,233
Teva Pharmaceutical Industries Ltd., ADR (a)	694		5,601
UCB SA	107		7,458
		$	909,298
Pipelines — 1.17%
APA Group	2,557		15,685
Enbridge, Inc.	1,315		48,760
Keyera Corp.	456		9,388
Pembina Pipeline Corp.	781		23,724
TC Energy Corp.	715		28,800
		$	126,357
Private Equity — 0.53%
3i Group PLC	512		6,248
Brookfield Asset Management, Inc., Class A	531		21,723
Capitaland Investment Ltd.	4,500		10,872
EQT AB	231		4,561
Eurazeo SE	167		8,813
Onex Corp.	109		5,000
		$	57,217
Real Estate — 1.72%
Azrieli Group Ltd.	116		7,943
CK Asset Holdings Ltd.	2,500		15,033
Daito Trust Construction Co. Ltd.	100		9,376
ESR Group Ltd. (b)	4,200		10,594
Fastighets AB Balder (a)	872		3,517
FirstService Corp.	95		11,308
Hang Lung Properties Ltd.	3,000		4,923
Henderson Land Development Co. Ltd.	3,000		8,408
Hongkong Land Holdings Ltd.	2,317		10,241
Hulic Co. Ltd.	1,300		9,548
New World Development Co. Ltd.	3,000		8,523
REA Group Ltd.	57		4,188
Sagax AB, Class B	228		3,784
Sino Land Co. Ltd.	8,000		10,579
Sun Hung Kai Properties Ltd.	1,500		16,596
Swire Properties Ltd.	6,200		13,348
Swiss Prime Site AG	135		10,809
UOL Group Ltd.	2,800		12,964
Wharf Real Estate Investment Co. Ltd.	3,000		13,644
		$	185,326
REITs — 1.63%
British Land Co. PLC	998		3,908
Canadian Apartment Properties REIT	160		4,876
CapitaLand Integrated Commercial Trust	8,417		11,252
CapLand Ascendas REIT	8,600		16,107
Covivio	74		3,591
Dexus	1,174		5,797
Gecina SA	49		3,863
Goodman Group	700		7,066
GPT Group	1,864		4,567
Klepierre SA	455		7,982
Land Securities Group PLC	1,430		8,332
Link REIT	3,100		21,681

See accompanying notes.

26

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
REITs (continued)
Mapletree Logistics Trust	8,500	$	9,232
Mapletree Pan Asia Commercial Trust	10,500		12,575
Mirvac Group	4,629		5,759
RioCan Real Estate Investment Trust	681		9,180
Scentre Group	7,260		11,795
Segro PLC	648		5,448
Stockland	4,904		10,258
Vicinity Centres	7,943		8,815
Warehouses De Pauw CVA	154		3,791
		$	175,875
Retail — 2.12%
Alimentation Couche-Tard, Inc.	648		26,087
Canadian Tire Corp. Ltd., Class A	111		11,816
Chow Tai Fook Jewellery Group Ltd.	5,200		9,791
Cie Financiere Richemont SA, Class B	316		30,194
Dollarama, Inc.	440		25,259
Domino's Pizza Enterprises Ltd.	103		3,394
JD Sports Fashion PLC	3,195		3,575
Kingfisher PLC	1,783		4,388
McDonald's Holdings Co. Japan Ltd.	300		10,447
Moncler SpA	128		5,318
Next PLC	87		4,664
Nitori Holdings Co. Ltd.	100		8,423
Pan Pacific International Holdings Corp.	800		14,151
Reece Ltd.	426		3,820
Restaurant Brands International, Inc.	437		23,246
Swatch Group AG	22		5,006
Swatch Group AG	103		4,359
USS Co. Ltd.	700		10,819
Welcia Holdings Co. Ltd.	500		10,554
Wesfarmers Ltd.	483		13,198
		$	228,509
Semiconductors — 2.20%
Advantest Corp.	300		13,888
ASM International NV	25		5,727
ASML Holding NV	315		133,859
Infineon Technologies AG	453		10,082
Renesas Electronics Corp. (a)	1,800		14,949
STMicroelectronics NV	263		8,311
SUMCO Corp.	800		9,331
Tokyo Electron Ltd.	100		24,667
Tower Semiconductor Ltd. (a)	360		15,728
		$	236,542
Shipbuilding — 0.08%
Kongsberg Gruppen ASA	275		8,385
Software — 1.44%
Constellation Software, Inc.	17		23,655
Dassault Systemes SE	256		8,966
Koei Tecmo Holdings Co. Ltd.	600		9,846
Konami Group Corp.	200		9,231
Nemetschek SE	86		4,149
Open Text Corp.	220		5,815
Oracle Corp. Japan	200		10,640
Sage Group PLC	1,553		12,089

See accompanying notes.

27

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Software (continued)
SAP SE	377	$	31,080
Square Enix Holdings Co. Ltd.	300		12,914
Temenos AG	62		4,238
TIS, Inc.	500		13,249
WiseTech Global Ltd.	271		9,014
		$	154,886
Telecommunications — 4.33%
BCE, Inc.	321		13,460
Bezeq The Israeli Telecommunication Corp. Ltd.	8,700		14,249
BT Group PLC	9,027		12,231
Deutsche Telekom AG	3,183		54,566
Elisa Oyj	233		10,584
Hikari Tsushin, Inc.	100		11,774
HKT Trust & HKT Ltd.	9,000		10,548
KDDI Corp.	1,200		35,180
Koninklijke KPN NV	4,563		12,396
Nice Ltd. (a)	33		6,289
Nippon Telegraph & Telephone Corp.	1,200		32,386
Nokia Oyj	2,085		9,033
Orange SA	1,917		17,375
Proximus SADP	458		4,756
Rogers Communications, Inc., Class B	417		16,063
Singapore Telecommunications Ltd.	8,700		16,113
SoftBank Corp.	3,000		29,983
SoftBank Group Corp.	900		30,470
Spark New Zealand Ltd.	3,628		10,152
Swisscom AG	31		14,562
Tele2 AB, Class B	658		5,692
Telefonica Deutschland Holding AG	4,146		8,423
Telefonica SA	5,019		16,606
Telenor ASA	673		6,160
Telia Co. AB	3,835		11,069
Telstra Corp. Ltd.	5,521		13,596
TELUS Corp.	927		18,408
Vodafone Group PLC	21,411		24,174
		$	466,298
Toys, Games & Hobbies — 0.56%
Bandai Namco Holdings, Inc.	300		19,553
Nintendo Co. Ltd.	1,000		40,448
		$	60,001
Transportation — 2.26%
AP Moller - Maersk A/S, Class B	3		5,483
AP Moller - Maersk A/S, Class A	3		5,331
Aurizon Holdings Ltd.	4,404		9,719
Canadian National Railway Co.	558		60,262
Canadian Pacific Railway Ltd.	881		58,810
Deutsche Post AG	340		10,368
DSV A/S	69		8,149
Getlink SE	705		10,989
Kuehne + Nagel International AG	30		6,142
Mitsui OSK Lines Ltd.	600		10,787
MTR Corp. Ltd.	2,500		11,481
Nippon Yusen KK	600		10,227
SG Holdings Co. Ltd.	700		9,576
SITC International Holdings Co. Ltd.	2,000		3,700

See accompanying notes.

28

	Schedule of Investments
	Principal International Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Transportation (continued)
TFI International, Inc.		59	$	5,339
Yamato Holdings Co. Ltd.		700		10,529
ZIM Integrated Shipping Services Ltd.		279		6,557
			$	243,449
Water — 0.16%
Severn Trent PLC		239		6,284
United Utilities Group PLC		1,065		10,569
			$	16,853
TOTAL COMMON STOCKS			$	10,594,913
PREFERRED STOCKS — 0.25%		Shares Held		Value
Auto Manufacturers — 0.08%
Bayerische Motoren Werke AG
	8.79%	136	$	8,917
Electronics — 0.05%
Sartorius AG
	0.36%	15	$	5,250
Household Products/Wares — 0.12%
Henkel AG & Co. KGaA
	3.04%, 08/07/2022	224	$	13,396
TOTAL PREFERRED STOCKS			$	27,563
INVESTMENT COMPANIES — 0.34%		Shares Held		Value
Money Market Fund — 0.34%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (c)		36,406	$	36,406
TOTAL INVESTMENT COMPANIES			$	36,406
Total Investments			$	10,658,882
Other Assets and Liabilities — 0.95%				102,059
Total Net Assets — 100.00%			$	10,760,941
(a)	Non-income producing security.
(b)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $142,052 or 1.32% of net assets.
(c)	Current yield shown is as of period end.

See accompanying notes. 29

Schedule of Investments

Principal International Adaptive Multi-Factor ETF

September 30, 2022 (unaudited)

Portfolio Summary (unaudited)
Location	Percent
Japan	20.03	%
Canada	13.41	%
United Kingdom	13.16	%
Switzerland	9.67	%
France	8.38	%
Australia	7.63	%
Hong Kong	4.12	%
Germany	3.86	%
Netherlands	3.28	%
Singapore	2.34	%
Spain	2.04	%
Denmark	1.77	%
Sweden	1.57	%
Italy	1.55	%
Israel	1.44	%
Norway	1.09	%
Finland	0.81	%
Belgium	0.70	%
Ireland	0.60	%
United States	0.46	%
New Zealand	0.39	%
Portugal	0.30	%
Luxemburg	0.19	%
Austria	0.17	%
Mongolia	0.05	%
Jordan	0.04	%
Other Assets and Liabilities	0.95	%
TOTAL NET ASSETS	100.00	%

See accompanying notes.

30

	Schedule of Investments
	Principal Investment Grade Corporate Active ETF
	September 30, 2022 (unaudited)
			Principal
BONDS — 90.68%			Amount		Value
Aerospace & Defense — 2.44%
Boeing Co.
3.25%, 02/01/2028		$	1,268,000	$	1,105,997
3.50%, 03/01/2039			102,000		68,100
5.71%, 05/01/2040			514,000		448,960
5.81%, 05/01/2050			112,000		97,327
				$	1,720,384
Agriculture — 1.45%
Altria Group, Inc.
3.40%, 02/04/2041			315,000		198,625
BAT Capital Corp.
2.26%, 03/25/2028			510,000		405,653
3.56%, 08/15/2027			477,000		418,888
				$	1,023,166
Airlines — 3.76%
Delta Air Lines, Inc./SkyMiles IP Ltd.
4.75%, 10/20/2028 (a)			482,262		449,157
Southwest Airlines Co.
5.13%, 06/15/2027			225,000		220,279
5.25%, 05/04/2025			1,108,000		1,106,862
United Airlines 2012-1 Class A Pass Through Trust
4.15%, 10/11/2025			121,432		114,905
United Airlines 2014-2 Class A Pass Through Trust
3.75%, 03/03/2028			101,526		92,056
United Airlines 2016-2 Class A Pass Through Trust
3.10%, 04/07/2030			869,580		670,774
				$	2,654,033
Auto Manufacturers — 0.27%
General Motors Co.
5.00%, 10/01/2028			208,000		191,333
Banks — 19.48%
Bank of America Corp.
(6-month Secured Overnight Financing Rate + 1.06%),
2.09%, 06/14/2029 (b)			1,425,000		1,158,004
(5-year Treasury Constant Maturity Rate + 1.20%),
2.48%, 09/21/2036 (b)			488,000		352,477
(6-month Secured Overnight Financing Rate + 1.93%),
2.68%, 06/19/2041 (b)			165,000		106,566
(6-month Secured Overnight Financing Rate + 1.88%),
2.83%, 10/24/2051 (b)			654,000		389,075
(5-year Treasury Constant Maturity Rate + 2.00%),
3.85%, 03/08/2037 (b)			333,000		268,665
(6-month Secured Overnight Financing Rate + 1.83%),
4.57%, 04/27/2033 (b)			464,000		415,598
Barclays PLC
(1-year Treasury Constant Maturity Rate + 1.30%),
3.33%, 11/24/2042 (b)			240,000		151,755
4.84%, 05/09/2028			992,000		864,733
Citigroup, Inc.
(6-month Secured Overnight Financing Rate + 1.94%),
3.79%, 03/17/2033 (b)			898,000		752,755
5.61%, 09/29/2026			705,000		701,110
Credit Suisse Group AG

See accompanying notes.

31

Schedule of Investments
Principal Investment Grade Corporate Active ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Banks (continued)
Credit Suisse Group AG (continued)
(6-month Secured Overnight Financing Rate + 0.98%),
1.31%, 02/02/2027 (a),(b)	$	614,000	$	498,470
(5-year Treasury Constant Maturity Rate + 4.89%),
5.25%, 02/11/2027 (a),(b),(c),(d)		737,000		517,533
Deutsche Bank AG
(6-month U.S. International Swaps and Derivative Association + 2.55%),
4.88%, 12/01/2032 (b)		275,000		215,696
First Republic Bank
4.63%, 02/13/2047		614,000		492,004
Goldman Sachs Group, Inc.
(6-month Secured Overnight Financing Rate + 1.41%),
3.10%, 02/24/2033 (b)		2,238,000		1,777,542
JPMorgan Chase & Co.
(3-month Term Secured Overnight Financing Rate + 0.70%),
1.04%, 02/04/2027 (b)		1,241,000		1,054,522
Morgan Stanley
(6-month Secured Overnight Financing Rate + 0.88%),
1.59%, 05/04/2027 (b)		300,000		259,226
(6-month Secured Overnight Financing Rate + 1.36%),
2.48%, 09/16/2036 (b)		439,000		314,600
(6-month Secured Overnight Financing Rate + 1.43%),
2.80%, 01/25/2052 (b)		351,000		211,898
(3-month USD LIBOR + 1.34%),
3.59%, 07/22/2028 (b)		640,000		575,738
5.00%, 11/24/2025		272,000		268,506
National Australia Bank Ltd.
2.33%, 08/21/2030 (a)		417,000		310,493
Natwest Group PLC
(3-month USD LIBOR + 1.91%),
5.08%, 01/27/2030 (b)		385,000		350,796
Standard Chartered PLC
(5-year Treasury Constant Maturity Rate + 5.66%),
6.00%, 07/26/2025 (a),(b),(c),(d)		340,000		301,641
UBS Group AG
(1-year Treasury Constant Maturity Rate + 1.75%),
4.75%, 05/12/2028 (a),(b)		310,000		291,002
Wells Fargo & Co.
(6-month Secured Overnight Financing Rate + 2.10%),
2.39%, 06/02/2028 (b)		821,000		704,088
(6-month Secured Overnight Financing Rate + 2.10%),
4.90%, 07/25/2033 (b)		241,000		222,186
Westpac Banking Corp.
(1-year Treasury Constant Maturity Rate + 2.68%),
5.41%, 08/10/2033 (b)		254,000		227,782
			$	13,754,461
Beverages — 1.57%
Anheuser-Busch InBev Worldwide, Inc.
4.38%, 04/15/2038		813,000		694,180
4.90%, 01/23/2031		276,000		271,379
5.45%, 01/23/2039		150,000		142,936
			$	1,108,495
Biotechnology — 0.31%
CSL Finance PLC
4.75%, 04/27/2052 (a)		250,000		215,107

See accompanying notes.

32

	Schedule of Investments
Principal Investment Grade Corporate Active ETF
	September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Chemicals — 0.20%
International Flavors & Fragrances, Inc.
1.83%, 10/15/2027 (a)	$	171,000	$	140,069
Commercial Services — 1.78%
CoStar Group, Inc.
2.80%, 07/15/2030 (a)		895,000		706,461
PayPal Holdings, Inc.
4.40%, 06/01/2032		591,000		550,833
			$	1,257,294
Computers — 0.55%
Apple, Inc.
3.95%, 08/08/2052		171,000		142,796
Dell International LLC/EMC Corp.
4.90%, 10/01/2026		255,000		245,649
			$	388,445
Construction Materials — 0.54%
Masco Corp.
1.50%, 02/15/2028		475,000		383,270
Diversified Financial Services — 5.29%
AerCap Ireland Capital DAC/AerCap Global Aviation Trust
2.45%, 10/29/2026		601,000		507,008
3.00%, 10/29/2028		702,000		562,980
3.85%, 10/29/2041		375,790		249,621
Ally Financial, Inc.
5.75%, 11/20/2025		241,000		233,745
8.00%, 11/01/2031		678,000		710,786
Aviation Capital Group LLC
1.95%, 01/30/2026 (a)		646,000		542,258
Avolon Holdings Funding Ltd.
2.75%, 02/21/2028 (a)		164,000		128,782
4.25%, 04/15/2026 (a)		365,000		327,284
5.50%, 01/15/2026 (a)		139,000		130,729
Blackstone Holdings Finance Co. LLC
2.85%, 08/05/2051 (a)		220,342		132,226
Brookfield Finance, Inc.
4.85%, 03/29/2029		225,000		210,361
			$	3,735,780
Electric — 7.93%
Ameren Illinois Co.
3.85%, 09/01/2032		230,000		207,240
CenterPoint Energy Houston Electric LLC
3.35%, 04/01/2051		135,000		96,784
Commonwealth Edison Co.
4.00%, 03/01/2049		331,000		263,414
DTE Energy Co.
3.40%, 06/15/2029		280,000		245,139
Duke Energy Carolinas LLC
3.55%, 03/15/2052		126,000		91,753
Duke Energy Florida LLC
3.85%, 11/15/2042		169,000		131,867
Duke Energy Ohio, Inc.
4.30%, 02/01/2049		209,000		168,775
Entergy Corp.
1.90%, 06/15/2028		211,000		173,125

See accompanying notes.

33

	Schedule of Investments
Principal Investment Grade Corporate Active ETF
	September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Electric (continued)
Evergy, Inc.
2.90%, 09/15/2029	$	210,000	$	173,489
ITC Holdings Corp.
4.95%, 09/22/2027 (a)		275,000		268,284
Monongahela Power Co.
3.55%, 05/15/2027 (a)		116,000		106,830
NextEra Energy Capital Holdings, Inc.
1.88%, 01/15/2027		194,000		168,351
2.44%, 01/15/2032		97,000		75,460
4.45%, 06/20/2025		139,000		136,571
NRG Energy, Inc.
2.00%, 12/02/2025 (a)		341,000		301,170
4.45%, 06/15/2029 (a)		210,000		182,154
NSTAR Electric Co.
4.95%, 09/15/2052		146,000		136,367
Ohio Edison Co.
5.50%, 01/15/2033		97,000		95,609
Pacific Gas & Electric Co.
1.70%, 11/15/2023		368,000		352,872
2.95%, 03/01/2026		474,000		418,165
4.95%, 06/08/2025		308,000		298,982
4.50%, 07/01/2040		419,121		304,917
Southern California Edison Co.
3.45%, 02/01/2052		103,000		69,266
4.88%, 03/01/2049		211,000		176,348
Southern Co.
(3-month USD LIBOR + 3.63%),
6.92%, 03/15/2057		410,000		400,775
Tampa Electric Co.
3.63%, 06/15/2050		117,000		85,419
Virginia Electric & Power Co.
3.80%, 04/01/2028		146,000		136,989
WEC Energy Group, Inc.
1.38%, 10/15/2027		283,000		233,088
5.00%, 09/27/2025		103,000		102,628
			$	5,601,831
Entertainment — 1.56%
Warnermedia Holdings, Inc.
4.28%, 03/15/2032 (a)		448,000		368,562
5.05%, 03/15/2042 (a)		578,000		432,485
5.39%, 03/15/2062 (a)		412,000		298,663
			$	1,099,710
Environmental Control — 0.51%
Waste Connections, Inc.
4.20%, 01/15/2033		399,000		361,479
Food — 2.86%
JBS USA LUX SA/JBS USA Food Co./JBS USA Finance, Inc.
3.63%, 01/15/2032 (a)		828,000		646,875
3.75%, 12/01/2031 (a)		241,000		192,930
4.38%, 02/02/2052 (a)		558,000		374,005
6.50%, 12/01/2052 (a)		215,000		191,015

See accompanying notes.

34

	Schedule of Investments
	Principal Investment Grade Corporate Active ETF
	September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Food (continued)
Kraft Heinz Foods Co.
4.88%, 10/01/2049	$	345,000	$	284,344
Mars, Inc.
2.38%, 07/16/2040 (a)		125,000		82,373
Pilgrim's Pride Corp.
3.50%, 03/01/2032 (a)		328,000		247,269
Sysco Corp.
3.15%, 12/14/2051		736		465
			$	2,019,276
Gas — 1.43%
CenterPoint Energy Resources Corp.
1.75%, 10/01/2030		418,000		321,595
NiSource, Inc.
0.95%, 08/15/2025		351,000		311,543
Piedmont Natural Gas Co., Inc.
3.50%, 06/01/2029		245,000		215,664
Southern California Gas Co.
2.55%, 02/01/2030		191,000		160,615
			$	1,009,417
Healthcare — Products — 1.27%
Boston Scientific Corp.
2.65%, 06/01/2030		787,000		653,003
Danaher Corp.
2.80%, 12/10/2051		374,000		240,610
			$	893,613
Healthcare — Services — 3.37%
Centene Corp.
2.45%, 07/15/2028		765,000		622,878
3.38%, 02/15/2030		1,555,000		1,271,212
HCA, Inc.
5.63%, 09/01/2028		208,000		198,207
UnitedHealth Group, Inc.
2.75%, 05/15/2040		148,000		103,628
4.75%, 05/15/2052		202,000		180,671
			$	2,376,596
Insurance — 5.39%
AIA Group Ltd.
3.20%, 09/16/2040 (a)		258,000		192,586
Arthur J Gallagher & Co.
2.40%, 11/09/2031		340,000		260,129
Athene Global Funding
1.45%, 01/08/2026 (a),(e)		300,000		260,837
2.50%, 03/24/2028 (a)		480,000		399,560
2.55%, 11/19/2030 (a)		180,000		137,326
Athene Holding Ltd.
3.45%, 05/15/2052		214,000		133,037
Corebridge Financial, Inc.
4.40%, 04/05/2052 (a)		209,000		158,852
Enstar Group Ltd.
3.10%, 09/01/2031		470,000		333,773
Everest Reinsurance Holdings, Inc.
3.13%, 10/15/2052		181,000		111,866

See accompanying notes.

35

Schedule of Investments
Principal Investment Grade Corporate Active ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Insurance (continued)
Markel Corp.
4.30%, 11/01/2047	$	303,000	$	233,321
Marsh & McLennan Cos., Inc.
2.90%, 12/15/2051		171,000		105,972
MetLife, Inc.
5.00%, 07/15/2052		167,000		152,231
New York Life Insurance Co.
3.75%, 05/15/2050 (a)		216,000		159,709
Swiss Re Finance Luxembourg SA
(5-year Treasury Constant Maturity Rate + 3.58%),
5.00%, 04/02/2049 (a),(b)		1,000,000		875,000
XLIT Ltd.
5.50%, 03/31/2045		313,000		289,326
			$	3,803,525
Internet — 0.64%
Amazon.com, Inc.
3.10%, 05/12/2051		368,000		257,627
Meta Platforms, Inc.
4.45%, 08/15/2052 (a)		241,000		196,676
			$	454,303
Lodging — 0.28%
Hyatt Hotels Corp.
1.80%, 10/01/2024		210,000		196,883
Media — 3.17%
Charter Communications Operating LLC/Charter Communications Operating
Capital
2.30%, 02/01/2032		285,000		203,515
Comcast Corp.
3.97%, 11/01/2047		516,000		394,537
Fox Corp.
4.71%, 01/25/2029		349,000		327,863
Paramount Global
2.90%, 01/15/2027		779,000		693,668
5.25%, 04/01/2044		160,000		119,548
Time Warner Cable LLC
5.50%, 09/01/2041		352,000		276,290
5.88%, 11/15/2040		271,000		223,091
			$	2,238,512
Mining — 0.80%
Newmont Corp.
2.25%, 10/01/2030		347,000		268,422
Yamana Gold, Inc.
2.63%, 08/15/2031		405,000		299,532
			$	567,954
Miscellaneous Manufacturers — 1.25%
GE Capital International Funding Unlimited Co.
4.42%, 11/15/2035		762,000		682,692
Parker-Hannifin Corp.
4.25%, 09/15/2027		209,000		199,062
			$	881,754

See accompanying notes.

36

	Schedule of Investments
Principal Investment Grade Corporate Active ETF
	September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Oil & Gas — 1.68%
Canadian Natural Resources Ltd.
4.95%, 06/01/2047	$	251,000	$	213,504
Devon Energy Corp.
4.50%, 01/15/2030		316,000		287,626
Exxon Mobil Corp.
3.00%, 08/16/2039		192,000		142,505
Marathon Oil Corp.
4.40%, 07/15/2027		334,000		311,852
Shell International Finance BV
3.13%, 11/07/2049		339,000		232,015
			$	1,187,502
Packaging & Containers — 0.23%
WRKCo, Inc.
3.00%, 06/15/2033		211,000		163,256
Pharmaceuticals — 5.51%
AbbVie, Inc.
4.05%, 11/21/2039		214,000		172,145
4.25%, 11/21/2049		410,000		329,135
Bayer U.S. Finance II LLC
4.63%, 06/25/2038 (a)		440,000		364,100
Becton Dickinson and Co.
3.70%, 06/06/2027		1,376,000		1,280,497
4.67%, 06/06/2047		176,000		151,103
4.69%, 12/15/2044		275,000		234,864
Bristol-Myers Squibb Co.
4.13%, 06/15/2039		300,000		262,197
Cigna Corp.
4.38%, 10/15/2028		486,000		458,904
CVS Health Corp.
5.05%, 03/25/2048		347,000		305,590
Merck & Co., Inc.
2.75%, 12/10/2051		140,000		91,180
Zoetis, Inc.
3.90%, 08/20/2028		264,000		244,437
			$	3,894,152
Pipelines — 2.53%
Eastern Gas Transmission & Storage, Inc.
3.00%, 11/15/2029		96,000		82,278
Enbridge, Inc.
2.50%, 08/01/2033		276,000		206,691
Energy Transfer LP
3.75%, 05/15/2030		589,000		498,743
4.95%, 06/15/2028		172,000		160,199
5.15%, 03/15/2045		344,000		270,714
Enterprise Products Operating LLC
4.20%, 01/31/2050		315,000		240,537
Kinder Morgan, Inc.
3.60%, 02/15/2051		175,000		113,458
Sabine Pass Liquefaction LLC
5.00%, 03/15/2027		224,000		214,901
			$	1,787,521

See accompanying notes.

37

	Schedule of Investments
Principal Investment Grade Corporate Active ETF
	September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Private Equity — 0.37%
KKR Group Finance Co. VIII LLC
3.50%, 08/25/2050 (a)	$	249,000	$	170,922
KKR Group Finance Co. X LLC
3.25%, 12/15/2051 (a)		140,000		91,084
			$	262,006
REITs — 2.10%
Invitation Homes Operating Partnership LP
2.00%, 08/15/2031		479,000		343,625
Kimco Realty Corp.
3.20%, 04/01/2032		254,000		206,336
Realty Income Corp.
3.10%, 12/15/2029		70		60
Spirit Realty LP
3.20%, 01/15/2027		795,000		697,360
3.20%, 02/15/2031		156,000		121,549
VICI Properties LP/VICI Note Co., Inc.
4.13%, 08/15/2030 (a)		135,000		112,755
			$	1,481,685
Semiconductors — 1.21%
Broadcom, Inc.
4.11%, 09/15/2028		133,000		119,814
KLA Corp.
3.30%, 03/01/2050		295,000		207,212
Micron Technology, Inc.
3.37%, 11/01/2041		185,000		118,944
NVIDIA Corp.
3.50%, 04/01/2040		368,000		285,855
3.50%, 04/01/2050		170,000		124,455
			$	856,280
Software — 3.06%
Fiserv, Inc.
4.40%, 07/01/2049		276,000		214,064
Oracle Corp.
2.80%, 04/01/2027		272,000		240,053
4.00%, 07/15/2046		428,000		289,252
Take-Two Interactive Software, Inc.
4.00%, 04/14/2032		168,000		145,900
VMware, Inc.
1.80%, 08/15/2028		187,000		148,249
4.65%, 05/15/2027		1,177,000		1,124,232
			$	2,161,750
Telecommunications — 4.12%
AT&T, Inc.
3.50%, 09/15/2053		1,450,000		966,194
T-Mobile USA, Inc.
3.38%, 04/15/2029		591,000		510,612
Verizon Communications, Inc.
2.36%, 03/15/2032		1,167,000		894,886
2.65%, 11/20/2040		827,000		539,003
			$	2,910,695

See accompanying notes.

38

		Schedule of Investments
		Principal Investment Grade Corporate Active ETF
		September 30, 2022 (unaudited)
			Principal
BONDS (continued)			Amount		Value
Transportation — 1.10%
Burlington Northern Santa Fe LLC
	4.38%, 09/01/2042	$	107,000	$	91,923
FedEx Corp.
	4.10%, 02/01/2045		301,000		218,219
Union Pacific Corp.
	2.95%, 03/10/2052		251,000		165,408
	3.50%, 02/14/2053		420,000		304,164
			$		779,714
Trucking & Leasing — 0.46%
SMBC Aviation Capital Finance DAC
	1.90%, 10/15/2026 (a)		393,000		327,347
Water — 0.21%
Essential Utilities, Inc.
	2.40%, 05/01/2031		190,000		148,347
TOTAL BONDS			$		64,036,945
INVESTMENT COMPANIES — 8.23%			Shares Held		Value
Money Market Funds — 8.23%
Principal Government Money Market Fund — Institutional Class 2.80% (f),(g),(h)			198,135		198,135
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (g)			5,616,876		5,616,876
TOTAL INVESTMENT COMPANIES			$		5,815,011
Total Investments			$		69,851,956
Other Assets and Liabilities — 1.09%					768,502
Total Net Assets — 100.00%			$		70,620,458
(a)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $11,830,581 or 16.75% of net assets.
(b)	Rate shown is as of period end. The rate may be a variable or floating rate or a fixed rate which may convert to a variable or
	floating rate in the future.
(c)	Perpetual security. Perpetual securities pay an indefinite stream of interest, but they may be called by the issuer at an earlier
	date. Date shown, if any, reflects the next call date or final legal maturity date. Rate shown is as of period end.
(d)	Security is a contingent convertible security, ("CoCo"). CoCo's are hybrid debt securities that may convert to equity or have
	their principal written down upon occurrence of certain "triggers". At the end of the period, the value of these securities
	totaled $819,174 or 1.16% of net assets.
(e)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $193,818 or
	0.27% of net assets.
(f)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(g)	Current yield shown is as of period end.
(h)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $198,135 or 0.28% of net assets.

See accompanying notes. 39

			Schedule of Investments
		Principal Investment Grade Corporate Active ETF
			September 30, 2022 (unaudited)
Portfolio Summary (unaudited)
Sector				Percent
Financial					32.62	%
Consumer, Non-cyclical					18.11	%
Utilities					9.57	%
Money Market Funds					8.23	%
Communications					7.94	%
Industrial					6.54	%
Consumer, Cyclical					5.87	%
Technology					4.82	%
Energy					4.21	%
Basic Materials					1.00	%
Other Assets and Liabilities					1.09	%
TOTAL NET ASSETS					100.00	%
			June 30, 2022	Purchases				Sales			September 30, 2022
Affiliated Securities			Value		Cost		Proceeds				Value
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	1,398,980	$	2,860,743		$	4,061,588		$	198,135
		$	1,398,980	$	2,860,743		$	4,061,588		$	198,135
								Realized Gain from			Change in
				Realized Gain/(Loss) on			Capital Gain				Unrealized
			Income (a)	Investments			Distributions				Gain/(Loss)
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	—	$	—		$	—		$	—
		$	—	$	—		$	—		$	—
(a) Amount excludes earnings from securities lending collateral.
											Value and Unrealized
								Notional			Appreciation/
Description and Expiration Date				Type	Futures Contracts			Amount			(Depreciation)
U.S. 10 Year Notes; December 2022				Short	12		$	1,389,000	$		44,389
U.S. Long Bond CBT; December 2022				Long	6			762,000			(3,325	)
U.S. Treasury Ultra Bond; December 2022				Long	14			2,050,000			(132,577	)
Total									$		(91,513	)

See accompanying notes. 40

	Schedule of Investments
	Principal Millennial Global Growth ETF
	September 30, 2022 (unaudited)
COMMON STOCKS — 99.64%	Shares Held		Value
Apparel — 5.62%
adidas AG	535	$	62,332
Carter's, Inc.	592		38,794
Columbia Sportswear Co.	602		40,515
Fila Holdings Corp.	2,289		50,077
Gildan Activewear, Inc.	1,532		43,309
Kering SA	194		87,184
Levi Strauss & Co., Class A	2,749		39,778
LVMH Moet Hennessy Louis Vuitton SE	174		104,091
NIKE, Inc., Class B	856		71,151
PVH Corp.	708		31,718
Ralph Lauren Corp.	479		40,681
SMCP SA (a),(b)	7,741		39,109
Torrid Holdings, Inc. (a)	8,965		37,384
Urban Outfitters, Inc. (a)	20,348		399,838
VF Corp.	2,027		60,627
		$	1,146,588
Beverages — 2.11%
Brown-Forman Corp., Class B	1,696		112,903
Constellation Brands, Inc., Class A	496		113,921
Fevertree Drinks PLC	2,520		23,565
Monster Beverage Corp. (a)	1,425		123,918
Treasury Wine Estates Ltd.	6,838		54,980
		$	429,287
Commercial Services — 2.67%
Aaron's Co., Inc.	2,705		26,293
Adyen NV (a),(b)	245		312,578
Global Payments, Inc.	842		90,978
GMO Payment Gateway, Inc.	600		41,249
Nuvei Corp. (a)	788		21,316
Paysafe Ltd. (a)	17,539		24,204
PROG Holdings, Inc. (a)	1,887		28,267
		$	544,885
Computers — 0.44%
Apple, Inc.	649		89,692
Construction Materials — 1.11%
Fortune Brands Home & Security, Inc.	1,525		81,877
Masco Corp.	2,227		103,979
Mohawk Industries, Inc. (a)	438		39,941
		$	225,797
Diversified Financial Services — 8.53%
Coinbase Global, Inc., Class A (a)	3,595		231,842
Discover Financial Services	6,179		561,795
Futu Holdings Ltd., ADR (a)	11,449		426,933
LexinFintech Holdings Ltd., ADR (a)	140,957		238,217
Lufax Holding Ltd., ADR	66,343		168,511
Rocket Cos., Inc., Class A	4,885		30,873
XP, Inc., Class A (a)	4,193		79,709
		$	1,737,880
Entertainment — 5.57%
CTS Eventim AG & Co. KGaA (a)	5,354		223,110
DraftKings, Inc., Class A (a)	2,792		42,271
HYBE Co. Ltd. (a)	2,196		207,213

See accompanying notes.

41

Schedule of Investments
Principal Millennial Global Growth ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Entertainment (continued)
Universal Music Group NV	18,476	$	349,944
Warner Music Group Corp., Class A	13,509		313,544
		$	1,136,082
Food — 3.19%
Albertsons Cos., Inc., Class A	3,406		84,673
Kroger Co.	11,869		519,269
Sprouts Farmers Market, Inc. (a)	1,700		47,175
		$	651,117
Home Builders — 0.76%
DR Horton, Inc.	1,566		105,470
Toll Brothers, Inc.	1,156		48,552
		$	154,022
Home Furnishings — 2.11%
Arhaus, Inc. (a),(c)	6,383		45,000
Sleep Number Corp. (a)	1,072		36,245
Sony Group Corp.	4,700		301,556
Tempur Sealy International, Inc.	1,945		46,952
		$	429,753
Internet — 27.15%
AfreecaTV Co. Ltd.	4,592		204,132
Alphabet, Inc., Class C (a)	4,876		468,827
D-MARKET Elektronik Hizmetler ve Ticaret A/S, ADR (a),(c)	26,193		25,229
eBay, Inc.	1,977		72,773
Expedia Group, Inc. (a)	2,326		217,923
Farfetch Ltd., Class A (a)	3,934		29,308
Hello Group, Inc.	64,557		298,253
iQIYI, Inc., ADR (a),(c)	82,285		222,992
JD.com, Inc., ADR	2,207		111,012
JOYY, Inc., ADR	15,227		395,902
Kakao Corp.	1,435		57,272
Kuaishou Technology (a),(b)	52,500		340,764
Lulu's Fashion Lounge Holdings, Inc. (a),(c)	8,013		37,341
Match Group, Inc. (a)	4,136		197,494
Meta Platforms, Inc., Class A (a)	512		69,468
Naspers Ltd., Class N	4,362		545,440
Netflix, Inc. (a)	1,818		428,030
Pinterest, Inc., Class A (a)	4,741		110,465
RealReal, Inc. (a)	7,483		11,225
Revolve Group, Inc. (a)	9,421		204,342
Rightmove PLC	7,136		38,420
Shutterstock, Inc.	585		29,350
Snap, Inc., Class A (a)	12,498		122,730
Temple & Webster Group Ltd. (a)	11,836		37,930
Tencent Holdings Ltd.	2,600		88,238
Tencent Music Entertainment Group, ADR (a)	114,796		466,072
THG PLC (a)	49,088		20,674
Trip.com Group Ltd., ADR (a)	21,484		586,728
Vipshop Holdings Ltd., ADR (a)	6,606		55,557
Weibo Corp. (a)	2,425		41,468
		$	5,535,359
Leisure Time — 2.66%
Camping World Holdings, Inc., Class A	18,276		462,748

See accompanying notes.

42

	Schedule of Investments
	Principal Millennial Global Growth ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Leisure Time (continued)
Shimano, Inc.	500	$	78,560
		$	541,308
Media — 4.55%
Comcast Corp., Class A	2,422		71,037
Fox Corp., Class B	3,177		90,545
Paramount Global, Class B	11,903		226,633
Sirius XM Holdings, Inc.	17,148		97,915
Vivendi SE	56,590		442,135
		$	928,265
Real Estate — 0.44%
REA Group Ltd.	1,220		89,626
REITs — 3.47%
EastGroup Properties, Inc.	566		81,697
Equity Residential	1,281		86,109
Prologis, Inc.	701		71,222
Rexford Industrial Realty, Inc.	1,546		80,392
Segro PLC	42,118		354,112
Warehouses De Pauw CVA	1,366		33,629
		$	707,161
Retail — 16.59%
Academy Sports & Outdoors, Inc.	1,380		58,208
American Eagle Outfitters, Inc.	3,233		31,457
ANTA Sports Products Ltd.	10,000		105,992
Bath & Body Works, Inc.	2,412		78,631
Bed Bath & Beyond, Inc. (a),(c)	15,047		91,636
Dick's Sporting Goods, Inc.	544		56,924
Foot Locker, Inc.	1,832		57,030
Frasers Group PLC (a)	7,123		53,923
Goldwin, Inc.	1,200		63,511
H & M Hennes & Mauritz AB, Class B (c)	9,179		85,573
Hibbett, Inc.	1,225		61,017
Home Depot, Inc.	2,274		627,488
Industria de Diseno Textil SA	33,846		705,874
Kingfisher PLC	17,684		43,518
Li Ning Co. Ltd.	14,771		113,093
Lowe's Cos., Inc.	564		105,925
Lululemon Athletica, Inc. (a)	312		87,223
Next PLC	1,587		85,072
Pandora A/S	1,302		61,629
Petco Health & Wellness Co., Inc. (a),(c)	2,775		30,969
Qurate Retail, Inc., Series A	11,413		22,940
Ryohin Keikaku Co. Ltd.	4,920		41,099
Signet Jewelers Ltd.	7,692		439,906
Starbucks Corp.	1,267		106,757
Truworths International Ltd.	14,892		41,015
Victoria's Secret & Co. (a)	1,057		30,780
Williams-Sonoma, Inc.	794		93,573
		$	3,380,763
Semiconductors — 0.25%
NVIDIA Corp.	421		51,105
Software — 5.06%
Bilibili, Inc., ADR (a),(c)	14,431		221,083

See accompanying notes.

43

	Schedule of Investments
	Principal Millennial Global Growth ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Software (continued)
DouYu International Holdings Ltd., ADR (a)		177,364	$	177,364
Fidelity National Information Services, Inc.		1,130		85,394
Fiserv, Inc. (a)		1,151		107,699
HUYA, Inc., ADR (a)		82,620		183,416
Kakao Games Corp. (a)		920		27,426
Microsoft Corp.		369		85,940
NetEase, Inc., ADR		1,388		104,933
XD, Inc. (a)		19,000		38,728
			$	1,031,983
Telecommunications — 2.87%
AT&T, Inc.		38,150		585,221
Toys, Games & Hobbies — 2.94%
Funko, Inc., Class A (a)		29,599		598,492
Transportation — 1.55%
Deutsche Post AG		2,559		78,035
FedEx Corp.		491		72,899
United Parcel Service, Inc., Class B		531		85,778
XPO Logistics, Inc. (a)		745		33,167
Yamato Holdings Co. Ltd.		3,100		46,629
			$	316,508
TOTAL COMMON STOCKS			$	20,310,894
INVESTMENT COMPANIES — 1.96%		Shares Held		Value
Money Market Funds — 1.96%
Principal Government Money Market Fund — Institutional Class 2.80% (d),(e),(f)		330,928	$	330,928
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (f)		69,049		69,049
TOTAL INVESTMENT COMPANIES			$	399,977
Total Investments			$	20,710,871
Other Assets and Liabilities — (1.60)%				(326,673	)
Total Net Assets — 100.00%			$	20,384,198
(a)	Non-income producing security.
(b)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $692,451 or 3.40% of net assets.
(c)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $310,650 or
	1.52% of net assets.
(d)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(e)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $330,928 or 1.62% of net assets.
(f)	Current yield shown is as of period end.

See accompanying notes.

			Schedule of Investments
			Principal Millennial Global Growth ETF
			September 30, 2022 (unaudited)
Portfolio Summary (unaudited)
Location				Percent
United States					51.86	%
Cayman Islands					22.05	%
Spain					3.46	%
France					3.30	%
Netherlands					3.24	%
United Kingdom					3.04	%
South Africa					2.88	%
Japan					2.81	%
Republic Of Korea					2.68	%
Bermuda					2.28	%
Germany					1.78	%
Australia					0.90	%
Sweden					0.42	%
Canada					0.32	%
Denmark					0.30	%
Belgium					0.16	%
Turkey					0.12	%
Other Assets and Liabilities					(1.60	)%
TOTAL NET ASSETS					100.00	%
			June 30, 2022	Purchases				Sales		September 30, 2022
Affiliated Securities			Value		Cost			Proceeds		Value
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	988,500	$	5,231,115		$	5,888,687	$	330,928
		$	988,500	$	5,231,115		$	5,888,687	$	330,928
							Realized Gain
					Realized			from		Change in
				Gain/(Loss) on			Capital Gain			Unrealized
			Income (a)	Investments			Distributions			Gain/(Loss)
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	—	$	—		$	—	$	—
		$	—	$	—		$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

45

Schedule of Investments
Principal Quality ETF
September 30, 2022 (unaudited)
COMMON STOCKS — 99.72%	Shares Held		Value
Advertising — 1.11%
Interpublic Group of Cos., Inc.	13,532	$	346,419
Aerospace & Defense — 1.41%
Lockheed Martin Corp.	1,141		440,757
Apparel — 2.30%
NIKE, Inc., Class B	4,613		383,433
Tapestry, Inc.	11,894		338,146
		$	721,579
Auto Manufacturers — 0.33%
Tesla, Inc. (a)	392		103,978
Banks — 4.90%
Bank of America Corp.	18,877		570,086
JPMorgan Chase & Co.	6,246		652,707
SVB Financial Group (a)	926		310,932
		$	1,533,725
Biotechnology — 3.19%
Gilead Sciences, Inc.	7,538		465,019
Regeneron Pharmaceuticals, Inc. (a)	775		533,874
		$	998,893
Commercial Services — 4.31%
Gartner, Inc. (a)	1,636		452,665
Moody's Corp.	1,557		378,522
PayPal Holdings, Inc. (a)	6,040		519,863
		$	1,351,050
Computers — 6.52%
Apple, Inc.	12,187		1,684,243
Fortinet, Inc. (a)	7,313		359,288
		$	2,043,531
Diversified Financial Services — 5.21%
Ameriprise Financial, Inc.	1,624		409,167
Mastercard, Inc., Class A	2,034		578,348
Visa, Inc., Class A	3,628		644,514
		$	1,632,029
Electrical Components & Equipment — 1.28%
AMETEK, Inc.	3,528		400,110
Electronics — 6.10%
Agilent Technologies, Inc.	3,459		420,441
Allegion PLC	3,640		326,435
Amphenol Corp., Class A	6,237		417,630
Mettler-Toledo International, Inc. (a)	342		370,769
TE Connectivity Ltd.	3,411		376,438
		$	1,911,713
Food — 2.85%
General Mills, Inc.	6,174		472,990
Mondelez International, Inc., Class A	7,666		420,327
		$	893,317
Healthcare — Products — 8.84%
Abbott Laboratories	5,320		514,763

See accompanying notes.

46

	Schedule of Investments
	Principal Quality ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Healthcare — Products (continued)
Bio-Techne Corp.		1,176	$	333,984
IDEXX Laboratories, Inc. (a)		1,184		385,747
Teleflex, Inc.		1,467		295,542
Thermo Fisher Scientific, Inc.		1,125		570,589
Waters Corp. (a)		1,225		330,174
West Pharmaceutical Services, Inc.		1,380		339,591
			$	2,770,390
Healthcare — Services — 7.49%
Charles River Laboratories International, Inc. (a)		1,785		351,288
IQVIA Holdings, Inc. (a)		2,044		370,250
Laboratory Corp. of America Holdings		1,800		368,658
Quest Diagnostics, Inc.		3,017		370,156
UnitedHealth Group, Inc.		1,756		886,850
			$	2,347,202
Insurance — 1.28%
Berkshire Hathaway, Inc., Class B (a)		138		36,849
Prudential Financial, Inc.		4,249		364,479
			$	401,328
Internet — 3.80%
Alphabet, Inc., Class A (a)		1,600		153,040
Alphabet, Inc., Class C (a)		5,712		549,209
Amazon.com, Inc. (a)		4,319		488,047
			$	1,190,296
Machinery — Diversified — 1.36%
IDEX Corp.		2,129		425,481
Media — 2.69%
Comcast Corp., Class A		13,748		403,229
FactSet Research Systems, Inc.		1,096		438,520
			$	841,749
Oil & Gas Services — 1.09%
Schlumberger NV		9,484		340,476
Pharmaceuticals — 10.88%
AbbVie, Inc.		4,496		603,408
Bristol-Myers Squibb Co.		7,287		518,033
Eli Lilly & Co.		2,093		676,771
Merck & Co., Inc.		6,999		602,754
Pfizer, Inc.		13,451		588,616
Zoetis, Inc.		2,835		420,402
			$	3,409,984
REITs — 1.04%
Weyerhaeuser Co.		11,373		324,813
Retail — 6.10%
Chipotle Mexican Grill, Inc. (a)		320		480,883
McDonald's Corp.		2,385		550,315
O'Reilly Automotive, Inc. (a)		700		492,345
Yum! Brands, Inc.		3,647		387,822
			$	1,911,365

See accompanying notes.

47

		Schedule of Investments
		Principal Quality ETF
		September 30, 2022 (unaudited)
COMMON STOCKS (continued)				Shares Held		Value
Semiconductors — 4.76%
Applied Materials, Inc.				4,671	$	382,695
Lam Research Corp.				951		348,066
QUALCOMM, Inc.				4,003		452,259
Teradyne, Inc.				4,086		307,063
					$	1,490,083
Software — 8.21%
Microsoft Corp.				9,191		2,140,584
Synopsys, Inc. (a)				1,412		431,380
					$	2,571,964
Telecommunications — 1.68%
Cisco Systems, Inc.				13,164		526,560
Transportation — 0.99%
FedEx Corp.				2,087		309,857
TOTAL COMMON STOCKS					$	31,238,649
INVESTMENT COMPANIES — 0.24%				Shares Held		Value
Money Market Fund — 0.24%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (b)				74,105	$	74,105
TOTAL INVESTMENT COMPANIES					$	74,105
Total Investments					$	31,312,754
Other Assets and Liabilities — 0.04%						12,503
Total Net Assets — 100.00%					$	31,325,257
(a)	Non-income producing security.
(b)	Current yield shown is as of period end.
	Portfolio Summary (unaudited)
Sector		Percent
Consumer, Non-cyclical		37.58	%
Technology		19.49	%
Financial		12.42	%
Industrial		11.13	%
Communications		9.27	%
Consumer, Cyclical		8.74	%
Energy		1.09	%
Money Market Fund		0.24	%
Other Assets and Liabilities		0.04	%
TOTAL NET ASSETS		100.00	%

See accompanying notes. 48

	Schedule of Investments
Principal Real Estate Active Opportunities ETF
	September 30, 2022 (unaudited)
COMMON STOCKS — 97.64%	Shares Held			Value
Entertainment — 3.16%
Marriott Vacations Worldwide Corp.	1,264		$	154,031
REITs — 94.48%
Alexandria Real Estate Equities, Inc.	1,693			237,342
American Homes 4 Rent, Class A	6,946			227,898
American Tower Corp.	1,419			304,659
Crown Castle, Inc.	1,414			204,394
CubeSmart	5,649			226,299
DiamondRock Hospitality Co.	17,117			128,549
Digital Realty Trust, Inc.	1,591			157,795
Equinix, Inc.	388			220,710
Equity LifeStyle Properties, Inc.	3,555			223,396
Extra Space Storage, Inc.	1,996			344,729
Invitation Homes, Inc.	10,368			350,127
Medical Properties Trust, Inc.	10,452			123,961
Rexford Industrial Realty, Inc.	6,298			327,496
SBA Communications Corp.	757			215,480
Sun Communities, Inc.	2,276			308,011
Terreno Realty Corp.	4,199			222,505
Ventas, Inc.	7,171			288,059
VICI Properties, Inc.	10,836			323,455
Welltower, Inc.	2,549			163,952
			$	4,598,817
TOTAL COMMON STOCKS			$	4,752,848
INVESTMENT COMPANIES — 2.56%	Shares Held			Value
Money Market Fund — 2.56%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (a)	124,473			124,473
TOTAL INVESTMENT COMPANIES			$	124,473
Total Investments			$	4,877,321
Other Assets and Liabilities — (0.20)%				(9,899	)
Total Net Assets — 100.00%			$	4,867,422
(a) Current yield shown is as of period end.
Portfolio Summary (unaudited)
Sector	Percent
Financial	94.48	%
Consumer, Cyclical	3.16	%
Money Market Fund	2.56	%
Other Assets and Liabilities	(0.20	)%
TOTAL NET ASSETS	100.00	%

See accompanying notes. 49

Schedule of Investments
Principal Spectrum Preferred Securities Active ETF
September 30, 2022 (unaudited)
		Principal
BONDS — 95.30%		Amount		Value
Banks — 41.61%
Bank of America Corp.
(5-year Treasury Constant Maturity Rate + 2.76%),
4.38%, 01/27/2027 (a),(b)	$	9,588,000	$	7,694,370
(5-year Treasury Constant Maturity Rate + 3.23%),
6.13%, 04/27/2027 (a),(b)		7,731,000		7,305,795
(3-month USD LIBOR + 4.55%),
6.30%, 03/10/2026 (a),(b)		600,000		589,380
Bank of Montreal
(5-year Treasury Constant Maturity Rate + 2.98%),
4.80%, 08/25/2024 (a),(b)		2,937,000		2,465,612
Bank of New York Mellon Corp.
(5-year Treasury Constant Maturity Rate + 3.35%),
3.70%, 03/20/2026 (a),(b)		9,047,000		7,964,473
(5-year Treasury Constant Maturity Rate + 2.63%),
3.75%, 12/20/2026 (a),(b)		3,412,000		2,635,770
(5-year Treasury Constant Maturity Rate + 4.36%),
4.70%, 09/20/2025 (a),(b)		568,000		543,860
Bank of Nova Scotia
(5-year Treasury Constant Maturity Rate + 4.55%),
4.90%, 06/04/2025 (a),(b)		4,041,000		3,607,479
Citigroup, Inc.
(5-year Treasury Constant Maturity Rate + 3.42%),
3.88%, 02/18/2026 (a),(b)		6,780,000		5,590,991
(5-year Treasury Constant Maturity Rate + 3.60%),
4.00%, 12/10/2025 (a),(b)		7,645,000		6,440,912
(3-month USD LIBOR + 3.91%),
5.95%, 05/15/2025 (a),(b)		2,002,000		1,811,904
Citizens Financial Group, Inc.
(5-year Treasury Constant Maturity Rate + 3.22%),
4.00%, 10/06/2026 (a),(b)		1,906,000		1,526,621
(5-year Treasury Constant Maturity Rate + 5.31%),
5.65%, 10/06/2025 (a),(b)		2,561,000		2,496,975
(3-month USD LIBOR + 3.16%),
6.38%, 04/06/2024 (a),(b)		2,306,000		2,133,050
Comerica, Inc.
(5-year Treasury Constant Maturity Rate + 5.29%),
5.63%, 07/01/2025 (a),(b)		536,000		525,661
Fifth Third Bancorp
(5-year Treasury Constant Maturity Rate + 4.22%),
4.50%, 09/30/2025 (a),(b)		848,000		780,089
Goldman Sachs Group, Inc.
(5-year Treasury Constant Maturity Rate + 2.92%),
3.65%, 08/10/2026 (a),(b)		1,611,000		1,236,443
(5-year Treasury Constant Maturity Rate + 2.97%),
3.80%, 05/10/2026 (a),(b)		1,269,000		983,270
(5-year Treasury Constant Maturity Rate + 2.95%),
4.13%, 11/10/2026 (a),(b)		4,257,000		3,384,315
(5-year Treasury Constant Maturity Rate + 3.62%),
5.50%, 08/10/2024 (a),(b)		8,183,000		7,855,680
HSBC Capital Funding Dollar 1 LP
(3-month USD LIBOR + 4.98%),
10.18%, 06/30/2030 (a),(b)		4,568,000		5,769,004
Huntington Bancshares, Inc.
(7-year Treasury Constant Maturity Rate + 4.05%),
4.45%, 10/15/2027 (a),(b)		1,787,000		1,590,418
(10-year Treasury Constant Maturity Rate + 4.95%),
5.63%, 07/15/2030 (a),(b)		5,716,000		5,296,745

See accompanying notes.

50

Schedule of Investments
Principal Spectrum Preferred Securities Active ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Banks (continued)
JPMorgan Chase & Co.
(5-year Treasury Constant Maturity Rate + 2.85%),
3.65%, 06/01/2026 (a),(b)	$	8,649,000	$	7,004,061
(3-month USD LIBOR + 3.78%),
6.75%, 02/01/2024 (a),(b)		4,128,000		4,090,543
M&T Bank Corp.
(5-year Treasury Constant Maturity Rate + 2.68%),
3.50%, 09/01/2026 (a),(b)		7,753,000		5,780,495
PNC Financial Services Group, Inc.
(5-year Treasury Constant Maturity Rate + 2.60%),
3.40%, 09/15/2026 (a),(b)		2,790,000		2,082,114
(5-year Treasury Constant Maturity Rate + 3.24%),
6.20%, 09/15/2027 (a),(b)		6,135,000		5,797,575
SVB Financial Group
(5-year Treasury Constant Maturity Rate + 3.20%),
4.00%, 05/15/2026 (a),(b)		2,149,000		1,631,555
(5-year Treasury Constant Maturity Rate + 3.07%),
4.25%, 11/15/2026 (a),(b)		5,769,000		4,246,690
Truist Financial Corp.
(5-year Treasury Constant Maturity Rate + 3.00%),
4.80%, 09/01/2024 (a),(b)		5,380,000		4,790,060
(5-year Treasury Constant Maturity Rate + 4.61%),
4.95%, 09/01/2025 (a),(b)		1,394,000		1,339,341
U.S. Bancorp
(5-year Treasury Constant Maturity Rate + 2.54%),
3.70%, 01/15/2027 (a),(b)		8,435,000		6,367,160
Wells Fargo & Co.
(5-year Treasury Constant Maturity Rate + 3.45%),
3.90%, 03/15/2026 (a),(b)		13,726,000		11,607,049
(3-month USD LIBOR + 3.99%),
5.88%, 06/15/2025 (a),(b)		4,331,000		4,123,319
			$	139,088,779
Diversified Financial Services — 10.73%
Ally Financial, Inc.
(5-year Treasury Constant Maturity Rate + 3.87%),
4.70%, 05/15/2026 (a),(b)		6,776,000		5,281,957
(7-year Treasury Constant Maturity Rate + 3.48%),
4.70%, 05/15/2028 (a),(b)		277,000		197,363
American Express Co.
(5-year Treasury Constant Maturity Rate + 2.85%),
3.55%, 09/15/2026 (a),(b)		9,372,000		7,222,780
Capital One Financial Corp.
(5-year Treasury Constant Maturity Rate + 3.16%),
3.95%, 09/01/2026 (a),(b)		5,733,000		4,500,405
Charles Schwab Corp.
(5-year Treasury Constant Maturity Rate + 3.17%),
4.00%, 06/01/2026 (a),(b)		12,069,000		9,899,063
(5-year Treasury Constant Maturity Rate + 4.97%),
5.38%, 06/01/2025 (a),(b)		3,774,000		3,670,215
Discover Financial Services
(5-year Treasury Constant Maturity Rate + 5.78%),
6.13%, 06/23/2025 (a),(b)		5,200,000		5,072,387
			$	35,844,170

See accompanying notes.

51

Schedule of Investments
Principal Spectrum Preferred Securities Active ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Electric — 12.40%
Algonquin Power & Utilities Corp.
(5-year Treasury Constant Maturity Rate + 3.25%),
4.75%, 01/18/2082 (a)	$	2,980,000	$	2,433,975
American Electric Power Co., Inc.
(5-year Treasury Constant Maturity Rate + 2.68%),
3.88%, 02/15/2062 (a)		2,881,000		2,258,031
CMS Energy Corp.
(5-year Treasury Constant Maturity Rate + 4.12%),
4.75%, 06/01/2050 (a)		2,451,000		2,071,095
Dominion Energy, Inc.
(5-year Treasury Constant Maturity Rate + 3.20%),
4.35%, 01/15/2027 (a),(b)		540,000		458,114
(5-year Treasury Constant Maturity Rate + 2.99%),
4.65%, 12/15/2024 (a),(b)		11,314,000		9,964,842
Duke Energy Corp.
(5-year Treasury Constant Maturity Rate + 2.32%),
3.25%, 01/15/2082 (a)		4,301,000		3,152,900
(5-year Treasury Constant Maturity Rate + 3.39%),
4.88%, 09/16/2024 (a),(b)		7,713,000		6,912,719
Emera, Inc.
(3-month USD LIBOR + 5.44%),
6.75%, 06/15/2076 (a)		5,727,000		5,431,223
Enel SpA
(5-year Swap rate + 5.88%),
8.75%, 09/24/2073		3,300,000		3,291,750
NextEra Energy Capital Holdings, Inc.
(5-year Treasury Constant Maturity Rate + 2.55%),
3.80%, 03/15/2082 (a)		4,468,000		3,506,919
Southern Co.
(5-year Treasury Constant Maturity Rate + 3.73%),
4.00%, 01/15/2051 (a)		2,206,000		1,977,017
			$	41,458,585
Gas — 1.37%
NiSource, Inc.
(5-year Treasury Constant Maturity Rate + 2.84%),
5.65%, 06/15/2023 (a),(b)		4,963,000		4,578,367
Hand/Machine Tools — 0.82%
Stanley Black & Decker, Inc.
(5-year Treasury Constant Maturity Rate + 2.66%),
4.00%, 03/15/2060 (a)		3,175,000		2,737,453
Insurance — 20.14%
Allstate Corp.
(3-month USD LIBOR + 2.94%),
5.75%, 08/15/2053 (a)		3,175,000		2,922,645
American International Group, Inc.
(3-month USD LIBOR + 2.87%),
5.75%, 04/01/2048 (a)		1,182,000		1,088,951
Argentum Netherlands BV for Swiss Re Ltd.
(3-month USD LIBOR + 3.78%),
5.63%, 08/15/2052 (a)		5,600,000		4,972,800
Argentum Netherlands BV for Zurich Insurance Co. Ltd.
(5-year Treasury Constant Maturity Rate + 3.27%),
5.13%, 06/01/2048 (a)		4,000,000		3,522,000

See accompanying notes.

52

Schedule of Investments
Principal Spectrum Preferred Securities Active ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Insurance (continued)
Cloverie PLC for Zurich Insurance Co. Ltd.
(3-month USD LIBOR + 4.92%),
5.63%, 06/24/2046 (a)	$	5,600,000	$	5,173,560
Equitable Holdings, Inc.
(5-year Treasury Constant Maturity Rate + 4.74%),
4.95%, 09/15/2025 (a),(b)		3,275,000		3,070,313
Liberty Mutual Group, Inc.
(5-year Treasury Constant Maturity Rate + 3.32%),
4.13%, 12/15/2051 (a),(c)		2,587,000		1,998,633
Meiji Yasuda Life Insurance Co.
(5-year Swap rate + 4.23%),
5.20%, 10/20/2045 (a),(c)		3,175,000		3,061,558
MetLife, Inc.
(5-year Treasury Constant Maturity Rate + 3.58%),
3.85%, 09/15/2025 (a),(b)		8,503,000		7,606,740
9.25%, 04/08/2068 (c)		1,400,000		1,616,436
Nippon Life Insurance Co.
(5-year Treasury Constant Maturity Rate + 2.65%),
2.75%, 01/21/2051 (a),(c)		4,193,000		3,267,573
(5-year Treasury Constant Maturity Rate + 2.60%),
2.90%, 09/16/2051 (a),(c)		2,368,000		1,830,561
Prudential Financial, Inc.
(5-year Treasury Constant Maturity Rate + 3.04%),
3.70%, 10/01/2050 (a)		8,312,000		6,564,818
(5-year Treasury Constant Maturity Rate + 3.16%),
5.13%, 03/01/2052 (a)		4,584,000		3,974,053
Sumitomo Life Insurance Co.
(5-year Treasury Constant Maturity Rate + 2.75%),
3.38%, 04/15/2081 (a),(c)		3,820,000		3,094,200
(3-month USD LIBOR + 4.44%),
6.50%, 09/20/2073 (a),(c)		6,371,000		6,355,645
Voya Financial, Inc.
(5-year Treasury Constant Maturity Rate + 3.36%),
6.13%, 09/15/2023 (a),(b)		3,175,000		3,077,055
Zurich Finance Ireland Designated Activity Co.
(5-year Treasury Constant Maturity Rate + 2.78%),
3.00%, 04/19/2051 (a)		6,000,000		4,133,700
			$	67,331,241
Oil & Gas — 1.61%
BP Capital Markets PLC
(5-year Treasury Constant Maturity Rate + 4.04%),
4.38%, 06/22/2025 (a),(b)		4,355,000		4,028,375
(5-year Treasury Constant Maturity Rate + 4.40%),
4.88%, 03/22/2030 (a),(b)		1,560,000		1,341,600
			$	5,369,975
Pipelines — 4.48%
Enbridge, Inc.
(5-year Treasury Constant Maturity Rate + 5.31%),
5.75%, 07/15/2080 (a)		1,825,000		1,605,544
(3-month USD LIBOR + 3.89%),
6.00%, 01/15/2077 (a)		4,732,000		4,233,781
7.63%, 01/15/2083		500,000		482,089
Enterprise Products Operating LLC
(3-month USD LIBOR + 3.03%),
5.25%, 08/16/2077 (a)		3,175,000		2,653,677

See accompanying notes.

53

	Schedule of Investments
	Principal Spectrum Preferred Securities Active ETF
	September 30, 2022 (unaudited)
				Principal
BONDS (continued)				Amount		Value
Pipelines (continued)
Transcanada Trust
	(6-month Secured Overnight Financing Rate + 4.42%),
	5.50%, 09/15/2079 (a)	$		6,937,000	$	6,000,505
					$	14,975,596
REITs — 0.71%
Scentre Group Trust 2
	(5-year Treasury Constant Maturity Rate + 4.38%),
	4.75%, 09/24/2080 (a),(c)			891,000		765,187
	(5-year Treasury Constant Maturity Rate + 4.69%),
	5.13%, 09/24/2080 (a),(c)			1,989,000		1,619,185
					$	2,384,372
Telecommunications — 1.43%
Vodafone Group PLC
	(5-year Treasury Constant Maturity Rate + 2.77%),
	4.13%, 06/04/2081 (a)			1,773,000		1,227,803
	(5-year Swap rate + 4.87%),
	7.00%, 04/04/2079 (a)			3,742,000		3,560,887
					$	4,788,690
TOTAL BONDS					$	318,557,228
INVESTMENT COMPANIES — 4.85%				Shares Held		Value
Money Market Fund — 4.85%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (d)				16,194,926	$	16,194,926
TOTAL INVESTMENT COMPANIES					$	16,194,926
Total Investments					$	334,752,154
Other Assets and Liabilities — (0.15)%						(488,078	)
Total Net Assets — 100.00%					$	334,264,076
(a)	Rate shown is as of period end. The rate may be a variable or floating rate or a fixed rate which may convert to a variable or
	floating rate in the future.
(b)	Perpetual security. Perpetual securities pay an indefinite stream of interest, but they may be called by the issuer at an earlier
	date. Date shown, if any, reflects the next call date or final legal maturity date. Rate shown is as of period end.
(c)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $23,608,978 or 7.06% of net assets.
(d)	Current yield shown is as of period end.
	Portfolio Summary (unaudited)
Sector		Percent
Financial		73.19	%
Utilities		13.77	%
Energy		6.09	%
Money Market Fund		4.85	%
Communications		1.43	%
Industrial		0.82	%
Other Assets and Liabilities		(0.15	)%
TOTAL NET ASSETS		100.00	%

See accompanying notes. 54

			Schedule of Investments
		Principal Spectrum Preferred Securities Active ETF
			September 30, 2022 (unaudited)
			June 30, 2022	Purchases			Sales		September 30, 2022
Affiliated Securities			Value		Cost		Proceeds		Value
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	2,707,203	$	1,822,552	$	4,529,755	$	—
		$	2,707,203	$	1,822,552	$	4,529,755	$	—
						Realized Gain
					Realized		from		Change in
				Gain/(Loss) on		Capital Gain			Unrealized
			Income (a)	Investments		Distributions			Gain/(Loss)
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	—	$	—	$	—	$	—
		$	—	$	—	$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

55

Schedule of Investments
Principal Spectrum Tax-Advantaged Dividend Active ETF
September 30, 2022 (unaudited)
PREFERRED STOCKS — 11.90%		Shares Held		Value
Banks — 5.48%
Associated Banc-Corp.; Series F
5.63%, 09/15/2025 (a)		2,070	$	50,301
Bank of America Corp.; Series NN
4.38%, 11/03/2025 (a)		4,380		80,066
Fulton Financial Corp.; Series A
5.13%, 01/15/2026 (a)		9,200		191,176
Morgan Stanley
6.50%, 10/15/2027 (a)		4,000		100,560
Morgan Stanley; Series I
(3-month USD LIBOR + 3.71%),
6.38%, 10/15/2024 (a)		17,030		420,982
Synovus Financial Corp.; Series E
(5-year Treasury Constant Maturity Rate + 4.13%),
5.88%, 07/01/2024 (a)		11,500		281,865
			$	1,124,950
Insurance — 3.87%
Allstate Corp.; Series H
5.10%, 10/15/2024 (a)		11,500		241,385
American International Group, Inc.; Series A
5.85%, 03/15/2024 (a)		8,019		192,937
MetLife, Inc.; Series F
4.75%, 03/15/2025 (a)		17,250		358,455
			$	792,777
Telecommunications — 2.55%
AT&T, Inc.; Series A
5.00%, 12/12/2024 (a)		11,381		233,652
AT&T, Inc.; Series C
4.75%, 02/18/2025 (a)		15,395		289,118
			$	522,770
TOTAL PREFERRED STOCKS			$	2,440,497
		Principal
BONDS — 85.23%		Amount		Value
Banks — 69.20%
Bank of America Corp.
(3-month USD LIBOR + 3.90%),
6.10%, 03/17/2025 (a),(b)	$	34,000	$	32,593
(3-month USD LIBOR + 4.55%),
6.30%, 03/10/2026 (a),(b)		575,000		564,822
Bank of New York Mellon Corp.
(5-year Treasury Constant Maturity Rate + 3.35%),
3.70%, 03/20/2026 (a),(b)		230,000		202,479
(5-year Treasury Constant Maturity Rate + 4.36%),
4.70%, 09/20/2025 (a),(b)		575,000		550,563
Bank of Nova Scotia
(5-year Treasury Constant Maturity Rate + 4.55%),
4.90%, 06/04/2025 (a),(b)		575,000		513,314
BNP Paribas SA
(5-year Treasury Constant Maturity Rate + 4.90%),
7.75%, 08/16/2029 (a),(b),(c),(d)		200,000		184,560
Citigroup, Inc.
(5-year Treasury Constant Maturity Rate + 3.42%),
3.88%, 02/18/2026 (a),(b)		655,000		540,133

See accompanying notes. 56

Schedule of Investments
Principal Spectrum Tax-Advantaged Dividend Active ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Banks (continued)
Citizens Financial Group, Inc.
(5-year Treasury Constant Maturity Rate + 5.31%),
5.65%, 10/06/2025 (a),(b)	$	575,000	$	560,625
Comerica, Inc.
(5-year Treasury Constant Maturity Rate + 5.29%),
5.63%, 07/01/2025 (a),(b)		575,000		563,908
Credit Agricole SA
(5-year Swap Rate + 4.90%),
7.88%, 01/23/2024 (a),(b),(d)		861,000		825,484
Credit Suisse Group AG
(5-year Treasury Constant Maturity Rate + 6.38%),
9.75%, 06/23/2027 (a),(b),(c),(d)		600,000		588,528
Fifth Third Bancorp
(5-year Treasury Constant Maturity Rate + 4.22%),
4.50%, 09/30/2025 (a),(b)		548,000		504,114
Goldman Sachs Group, Inc.
(5-year Treasury Constant Maturity Rate + 2.97%),
3.80%, 05/10/2026 (a),(b)		438,000		339,379
HSBC Holdings PLC
(6-month U.S. International Swaps and Derivative Association + 4.37%),
6.38%, 03/30/2025 (a),(b),(d)		861,000		775,718
Huntington Bancshares, Inc.
(10-year Treasury Constant Maturity Rate + 4.95%),
5.63%, 07/15/2030 (a),(b)		575,000		532,825
ING Groep NV
(5-year Treasury Constant Maturity Rate + 4.34%),
5.75%, 11/16/2026 (a),(b),(d)		861,000		740,199
JPMorgan Chase & Co.
(5-year Treasury Constant Maturity Rate + 2.85%),
3.65%, 06/01/2026 (a),(b)		110,000		89,079
Lloyds Banking Group PLC
(5-year Swap Rate + 4.50%),
7.50%, 09/27/2025 (a),(b),(d)		861,000		785,662
M&T Bank Corp.
(3-month USD LIBOR + 3.52%),
5.13%, 11/01/2026 (a),(b)		247,000		218,595
Natwest Group PLC
(5-year Swap Rate + 5.72%),
8.00%, 08/10/2025 (a),(b),(d)		861,000		803,494
Nordea Bank Abp
(5-year Treasury Constant Maturity Rate + 4.11%),
6.63%, 03/26/2026 (a),(b),(c),(d)		861,000		795,133
PNC Financial Services Group, Inc.
(5-year Treasury Constant Maturity Rate + 3.00%),
6.00%, 05/15/2027 (a),(b)		400,000		371,000
(5-year Treasury Constant Maturity Rate + 3.24%),
6.20%, 09/15/2027 (a),(b)		100,000		94,500
Societe Generale SA
(5-year Swap rate + 4.98%),
7.88%, 12/18/2023 (a),(b),(d)		824,000		790,010
SVB Financial Group
(5-year Treasury Constant Maturity Rate + 3.20%),
4.00%, 05/15/2026 (a),(b)		110,000		83,514
Truist Financial Corp.
(5-year Treasury Constant Maturity Rate + 4.61%),
4.95%, 09/01/2025 (a),(b)		575,000		552,454

See accompanying notes.

57

Schedule of Investments
Principal Spectrum Tax-Advantaged Dividend Active ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Banks (continued)
U.S. Bancorp
(5-year Treasury Constant Maturity Rate + 2.54%),
3.70%, 01/15/2027 (a),(b)	$	209,000	$	157,764
UBS Group AG
(5-year Swap rate + 4.34%),
7.00%, 01/31/2024 (a),(b),(d)		861,000		814,678
Wells Fargo & Co.
(5-year Treasury Constant Maturity Rate + 3.45%),
3.90%, 03/15/2026 (a),(b)		328,000		277,365
(3-month USD LIBOR + 3.99%),
5.88%, 06/15/2025 (a),(b)		355,000		337,977
			$	14,190,469
Diversified Financial Services — 8.41%
Ally Financial, Inc.
(5-year Treasury Constant Maturity Rate + 3.87%),
4.70%, 05/15/2026 (a),(b)		220,000		171,492
Capital One Financial Corp.
(5-year Treasury Constant Maturity Rate + 3.16%),
3.95%, 09/01/2026 (a),(b)		209,000		164,065
Charles Schwab Corp.
(5-year Treasury Constant Maturity Rate + 3.17%),
4.00%, 06/01/2026 (a),(b)		328,000		269,027
(5-year Treasury Constant Maturity Rate + 4.97%),
5.38%, 06/01/2025 (a),(b)		575,000		559,188
Discover Financial Services
(5-year Treasury Constant Maturity Rate + 5.78%),
6.13%, 06/23/2025 (a),(b)		575,000		560,889
			$	1,724,661
Electric — 4.49%
Dominion Energy, Inc.
(5-year Treasury Constant Maturity Rate + 2.99%),
4.65%, 12/15/2024 (a),(b)		460,000		405,146
Duke Energy Corp.
(5-year Treasury Constant Maturity Rate + 3.39%),
4.88%, 09/16/2024 (a),(b)		575,000		515,340
			$	920,486
Insurance — 3.13%
MetLife, Inc.
(5-year Treasury Constant Maturity Rate + 3.58%),
3.85%, 09/15/2025 (a),(b)		220,000		196,811
Voya Financial, Inc.
(5-year Treasury Constant Maturity Rate + 3.36%),
6.13%, 09/15/2023 (a),(b)		460,000		445,809
			$	642,620
TOTAL BONDS			$	17,478,236

See accompanying notes. 58

		Schedule of Investments
	Principal Spectrum Tax-Advantaged Dividend Active ETF
		September 30, 2022 (unaudited)
INVESTMENT COMPANIES — 1.99%		Shares Held		Value
Money Market Fund — 1.99%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (e)		407,069	$	407,069
TOTAL INVESTMENT COMPANIES		$		407,069
Total Investments		$		20,325,802
Other Assets and Liabilities — 0.88%				181,406
Total Net Assets — 100.00%		$		20,507,208
(a)	Perpetual security. Perpetual securities pay an indefinite stream of interest, but they may be called by the issuer at an earlier
	date. Date shown, if any, reflects the next call date or final legal maturity date. Rate shown is as of period end.
(b)	Rate shown is as of period end. The rate may be a variable or floating rate or a fixed rate which may convert to a variable or
	floating rate in the future.
(c)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $1,568,221 or 7.65% of net assets.
(d)	Security is a contingent convertible security, ("CoCo"). CoCo's are hybrid debt securities that may convert to equity or have
	their principal written down upon occurrence of certain "triggers". At the end of the period, the value of these securities
	totaled $7,103,466 or 34.64% of net assets.
(e)	Current yield shown is as of period end.
	Portfolio Summary (unaudited)
Sector		Percent
Financial		90.09	%
Utilities		4.49	%
Communications		2.55	%
Money Market Fund		1.99	%
Other Assets and Liabilities		0.88	%
TOTAL NET ASSETS		100.00	%

See accompanying notes. 59

Schedule of Investments
Principal Ultra-Short Active Income ETF
September 30, 2022 (unaudited)
		Principal
BONDS — 87.21%		Amount		Value
Asset-Backed Securities — 21.63%
CPS Auto Receivables Trust 2021-B
0.37%, 03/17/2025 (a)	$	1,647	$	1,644
CPS Auto Receivables Trust 2021-C
0.33%, 07/15/2024 (a)		5,021		5,014
CPS Auto Receivables Trust 2022-A
0.98%, 04/16/2029 (a)		84,129		82,564
CPS Auto Receivables Trust 2022-C
4.18%, 04/15/2030 (a)		90,404		89,884
Ford Credit Auto Owner Trust 2018-REV2
3.47%, 01/15/2030 (a)		100,000		99,041
GM Financial Consumer Automobile Receivables Trust 2022-3
(1-month Secured Overnight Financing Rate + 0.60%),
2.89%, 09/16/2025		250,000		249,979
GreatAmerica Leasing Receivables Funding LLC
0.27%, 06/15/2023 (a)		8,972		8,944
Madison Park Funding XVIII Ltd.
(3-month USD LIBOR + 0.94%),
3.67%, 10/21/2030 (a)		250,000		244,561
Navistar Financial Dealer Note Master Owner Trust II
(1-month Secured Overnight Financing Rate + 1.25%),
3.53%, 05/25/2027 (a)		200,000		200,292
Santander Drive Auto Receivables Trust
3.98%, 01/15/2025		100,000		99,377
TCI-Flatiron CLO 2016-1 Ltd.
(3-month Term Secured Overnight Financing Rate + 1.10%),
3.58%, 01/17/2032 (a)		250,000		244,630
Trafigura Securitisation Finance PLC 2021-1
(1-month USD LIBOR + 0.53%),
3.35%, 01/15/2025 (a)		250,000		241,591
Westlake Automobile Receivables Trust 2022-1
1.97%, 12/16/2024 (a)		179,204		177,553
Westlake Automobile Receivables Trust 2022-2
(1-month Secured Overnight Financing Rate + 1.13%),
3.42%, 08/15/2025 (a)		40,000		39,997
World Omni Select Auto Trust 2021-A
0.29%, 02/18/2025		38,212		38,034
			$	1,823,105
Banks — 35.37%
Bank of America Corp.
(3-month USD LIBOR + 0.79%),
3.00%, 12/20/2023 (b)		250,000		248,673
Bank of Montreal
(3-month Secured Overnight Financing Rate Index + 0.71%),
3.56%, 03/08/2024		200,000		199,396
Bank of New York Mellon Corp.
(3-month Secured Overnight Financing Rate + 0.26%),
2.73%, 04/26/2024		250,000		248,715
Citigroup, Inc.
3.50%, 05/15/2023		200,000		198,578
Citizens Bank NA
(6-month Secured Overnight Financing Rate + 1.40%),
4.12%, 05/23/2025 (b),(c)		250,000		245,161
Credit Suisse AG
(3-month Secured Overnight Financing Rate Index + 0.38%),
3.00%, 08/09/2023		250,000		247,961

See accompanying notes.

60

Schedule of Investments
Principal Ultra-Short Active Income ETF
September 30, 2022 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Banks (continued)
Goldman Sachs Group, Inc.
(3-month Secured Overnight Financing Rate + 0.54%),
3.23%, 11/17/2023	$	250,000	$	249,338
JPMorgan Chase & Co.
(3-month USD LIBOR + 1.23%),
4.01%, 10/24/2023		250,000		250,000
Morgan Stanley
(3-month USD LIBOR + 1.40%),
4.18%, 10/24/2023		250,000		250,005
MUFG Union Bank NA
(3-month Secured Overnight Financing Rate + 0.71%),
3.58%, 12/09/2022		300,000		299,901
Royal Bank of Canada
(3-month Secured Overnight Financing Rate Index + 0.36%),
2.90%, 07/29/2024		250,000		246,967
Toronto-Dominion Bank
(3-month Secured Overnight Financing Rate + 0.24%),
2.40%, 01/06/2023		200,000		199,794
Wells Fargo & Co.
(6-month Secured Overnight Financing Rate + 1.60%),
1.65%, 06/02/2024 (b),(c)		100,000		97,651
			$	2,982,140
Biotechnology — 2.14%
Gilead Sciences, Inc.
0.75%, 09/29/2023		188,000		180,437
Diversified Financial Services — 4.11%
AerCap Ireland Capital DAC/AerCap Global Aviation Trust
(3-month Secured Overnight Financing Rate + 0.68%),
3.65%, 09/29/2023		150,000		146,810
American Express Co.
(3-month Secured Overnight Financing Rate Index + 0.72%),
3.31%, 05/03/2024		200,000		199,335
			$	346,145
Electric — 10.31%
American Electric Power Co., Inc.
2.03%, 03/15/2024		200,000		191,413
Black Hills Corp.
1.04%, 08/23/2024		250,000		230,891
Dominion Energy, Inc.
(3-month USD LIBOR + 0.53%),
3.82%, 09/15/2023		150,000		149,300
Florida Power & Light Co.
(3-month Secured Overnight Financing Rate Index + 0.25%),
2.89%, 05/10/2023		100,000		99,695
NextEra Energy Capital Holdings, Inc.
(3-month Secured Overnight Financing Rate Index + 0.40%),
2.99%, 11/03/2023		200,000		198,159
			$	869,458
Entertainment — 1.18%
Warnermedia Holdings, Inc.
(3-month Secured Overnight Financing Rate Index + 1.78%),
4.68%, 03/15/2024 (a)		100,000		99,742

See accompanying notes.

61

	Schedule of Investments
	Principal Ultra-Short Active Income ETF
	September 30, 2022 (unaudited)
				Principal
BONDS (continued)				Amount		Value
Healthcare — Products — 2.84%
PerkinElmer, Inc.
	0.55%, 09/15/2023		$	250,000	$	239,154
Oil & Gas — 2.86%
ConocoPhillips Co.
	2.13%, 03/08/2024			250,000		241,354
Pipelines — 2.97%
Kinder Morgan, Inc.
	(3-month USD LIBOR + 1.28%),
	3.79%, 01/15/2023			250,000		250,226
Telecommunications — 3.80%
NTT Finance Corp.
	0.37%, 03/03/2023 (a)			200,000		196,786
Sprint Spectrum Co. LLC/Sprint Spectrum Co. II LLC/Sprint Spectrum Co. III
LLC
	4.74%, 03/20/2025 (a)			125,000		123,199
					$	319,985
TOTAL BONDS					$	7,351,746
U.S. GOVERNMENT & GOVERNMENT AGENCY OBLIGATIONS —
5.91		%
U.S. Treasury Notes — 5.91%
	2.13%, 12/31/2022		$	500,000	$	498,303
TOTAL U.S. GOVERNMENT & GOVERNMENT AGENCY OBLIGATIONS					$	498,303
INVESTMENT COMPANIES — 6.95%				Shares Held		Value
Money Market Funds — 6.95%
Principal Government Money Market Fund — Institutional Class 2.80% (d),(e),(f)				39,260	$	39,260
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (d)				546,322		546,322
					$	585,582
TOTAL INVESTMENT COMPANIES					$	585,582
Total Investments					$	8,435,631
Other Assets and Liabilities — (0.07)%						(5,607	)
Total Net Assets — 100.00%					$	8,430,024
(a)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $1,855,442 or 22.01% of net assets.
(b)	Rate shown is as of period end. The rate may be a variable or floating rate or a fixed rate which may convert to a variable or
	floating rate in the future.
(c)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $38,466 or
	0.46% of net assets.
(d)	Current yield shown is as of period end.
(e)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(f)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $39,260 or 0.47% of net assets.

See accompanying notes. 62

			Schedule of Investments
			Principal Ultra-Short Active Income ETF
			September 30, 2022 (unaudited)
Portfolio Summary (unaudited)
Sector				Percent
Financial					39.48	%
Asset Backed Securities					21.63	%
Utilities					10.31	%
Money Market Funds					6.95	%
Government					5.91	%
Energy					5.83	%
Consumer, Non-cyclical					4.98	%
Communications					3.80	%
Consumer, Cyclical					1.18	%
Other Assets and Liabilities					(0.07	)%
TOTAL NET ASSETS					100.00	%
			June 30, 2022	Purchases				Sales		September 30, 2022
Affiliated Securities			Value		Cost			Proceeds		Value
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	66,468	$	872,610		$	899,818	$	39,260
		$	66,468	$	872,610		$	899,818	$	39,260
							Realized Gain
					Realized			from		Change in
				Gain/(Loss) on			Capital Gain			Unrealized
			Income (a)	Investments			Distributions			Gain/(Loss)
Principal Government Money
Market Fund — Institutional Class
2.80	%	$	—	$	—		$	—	$	—
		$	—	$	—		$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

63

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS — 99.64%	Shares Held		Value
Advertising — 0.14%
Omnicom Group, Inc.	120	$	7,571
Aerospace & Defense — 1.99%
General Dynamics Corp.	56		11,881
Howmet Aerospace, Inc.	111		3,433
L3Harris Technologies, Inc.	72		14,964
Lockheed Martin Corp.	63		24,336
Northrop Grumman Corp.	44		20,694
Raytheon Technologies Corp.	258		21,120
Teledyne Technologies, Inc. (a)	21		7,087
TransDigm Group, Inc.	8		4,199
		$	107,714
Agriculture — 0.86%
Altria Group, Inc.	374		15,102
Archer-Daniels-Midland Co.	125		10,056
Philip Morris International, Inc.	259		21,500
		$	46,658
Airlines — 0.06%
United Airlines Holdings, Inc. (a)	99		3,221
Apparel — 0.20%
NIKE, Inc., Class B	91		7,564
Tapestry, Inc.	108		3,070
		$	10,634
Auto Manufacturers — 2.69%
Cummins, Inc.	25		5,088
Ford Motor Co.	420		4,704
PACCAR, Inc.	118		9,875
Tesla, Inc. (a)	475		125,994
		$	145,661
Auto Parts & Equipment — 0.06%
BorgWarner, Inc.	96		3,014
Banks — 2.82%
Bank of New York Mellon Corp.	126		4,854
Comerica, Inc.	46		3,271
First Republic Bank	27		3,525
Goldman Sachs Group, Inc.	34		9,964
Huntington Bancshares, Inc.	301		3,967
JPMorgan Chase & Co.	328		34,276
KeyCorp	223		3,572
M&T Bank Corp.	56		9,874
Morgan Stanley	232		18,330
Northern Trust Corp.	94		8,043
PNC Financial Services Group, Inc.	49		7,322
Regions Financial Corp.	190		3,813
Signature Bank	18		2,718
Truist Financial Corp.	421		18,330
U.S. Bancorp	167		6,733
Wells Fargo & Co.	273		10,980
Zions Bancorp NA	61		3,102
		$	152,674
Beverages — 2.66%
Brown-Forman Corp., Class B	157		10,452

See accompanying notes.

64

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Beverages (continued)
Coca-Cola Co.	841	$	47,113
Constellation Brands, Inc., Class A	46		10,565
Keurig Dr Pepper, Inc.	388		13,898
Molson Coors Beverage Co., Class B	71		3,407
Monster Beverage Corp. (a)	113		9,826
PepsiCo, Inc.	299		48,815
		$	144,076
Biotechnology — 1.73%
Amgen, Inc.	133		29,978
Corteva, Inc.	193		11,030
Gilead Sciences, Inc.	253		15,608
Incyte Corp. (a)	161		10,729
Regeneron Pharmaceuticals, Inc. (a)	19		13,089
Vertex Pharmaceuticals, Inc. (a)	47		13,608
		$	94,042
Chemicals — 1.37%
Air Products and Chemicals, Inc.	29		6,749
Albemarle Corp.	17		4,496
CF Industries Holdings, Inc.	77		7,411
Dow, Inc.	226		9,928
DuPont de Nemours, Inc.	84		4,234
FMC Corp.	36		3,805
Linde PLC	82		22,106
LyondellBasell Industries NV, Class A	53		3,990
Mosaic Co.	143		6,911
Sherwin-Williams Co.	24		4,914
		$	74,544
Commercial Services — 2.27%
Automatic Data Processing, Inc.	112		25,333
Cintas Corp.	37		14,363
CoStar Group, Inc. (a)	56		3,900
Equifax, Inc.	20		3,429
FleetCor Technologies, Inc. (a)	16		2,819
Gartner, Inc. (a)	12		3,320
Global Payments, Inc.	34		3,674
MarketAxess Holdings, Inc.	12		2,670
Moody's Corp.	40		9,724
Nielsen Holdings PLC	130		3,604
PayPal Holdings, Inc. (a)	88		7,574
Quanta Services, Inc.	30		3,822
Robert Half International, Inc.	38		2,907
Rollins, Inc.	180		6,242
S&P Global, Inc.	59		18,016
United Rentals, Inc. (a)	12		3,241
Verisk Analytics, Inc.	51		8,697
		$	123,335
Computers — 8.35%
Accenture PLC, Class A	100		25,730
Apple, Inc.	2,702		373,416
Cognizant Technology Solutions Corp., Class A	156		8,961
EPAM Systems, Inc. (a)	9		3,260
Fortinet, Inc. (a)	84		4,127
Hewlett Packard Enterprise Co.	305		3,654
HP, Inc.	161		4,012

See accompanying notes.

65

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Computers (continued)
International Business Machines Corp.	162	$	19,247
Leidos Holdings, Inc.	119		10,409
		$	452,816
Construction Materials — 0.44%
Carrier Global Corp.	109		3,876
Fortune Brands Home & Security, Inc.	48		2,577
Martin Marietta Materials, Inc.	27		8,696
Vulcan Materials Co.	56		8,832
		$	23,981
Distribution/Wholesale — 0.64%
Copart, Inc. (a)	34		3,617
Fastenal Co.	192		8,840
LKQ Corp.	142		6,695
Pool Corp.	10		3,182
WW Grainger, Inc.	25		12,230
		$	34,564
Diversified Financial Services — 3.06%
Ameriprise Financial, Inc.	15		3,779
BlackRock, Inc.	12		6,603
Cboe Global Markets, Inc.	66		7,746
Charles Schwab Corp.	116		8,337
CME Group, Inc.	110		19,484
Franklin Resources, Inc.	260		5,595
Intercontinental Exchange, Inc.	128		11,565
Invesco Ltd.	178		2,439
Mastercard, Inc., Class A	129		36,680
Nasdaq, Inc.	136		7,709
Raymond James Financial, Inc.	73		7,214
T Rowe Price Group, Inc.	34		3,570
Visa, Inc., Class A	253		44,946
		$	165,667
Electric — 4.70%
AES Corp.	154		3,480
Alliant Energy Corp.	189		10,015
Ameren Corp.	101		8,136
American Electric Power Co., Inc.	127		10,979
CenterPoint Energy, Inc.	276		7,778
CMS Energy Corp.	131		7,629
Consolidated Edison, Inc.	109		9,348
Constellation Energy Corp.	53		4,409
Dominion Energy, Inc.	182		12,578
DTE Energy Co.	73		8,399
Duke Energy Corp.	156		14,511
Edison International	141		7,978
Entergy Corp.	80		8,050
Evergy, Inc.	172		10,217
Eversource Energy	161		12,552
Exelon Corp.	270		10,114
FirstEnergy Corp.	221		8,177
NextEra Energy, Inc.	320		25,091
NRG Energy, Inc.	83		3,176
Pinnacle West Capital Corp.	100		6,451
PPL Corp.	310		7,859
Public Service Enterprise Group, Inc.	157		8,828

See accompanying notes.

66

Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Electric (continued)
Sempra Energy	77	$	11,545
Southern Co.	214		14,552
WEC Energy Group, Inc.	102		9,122
Xcel Energy, Inc.	216		13,824
		$	254,798
Electrical Components & Equipment — 0.41%
AMETEK, Inc.	77		8,733
Emerson Electric Co.	147		10,763
Generac Holdings, Inc. (a)	16		2,850
		$	22,346
Electronics — 1.01%
Agilent Technologies, Inc.	35		4,254
Allegion PLC	75		6,726
Amphenol Corp., Class A	153		10,245
Fortive Corp.	145		8,454
Garmin Ltd.	37		2,972
Honeywell International, Inc.	66		11,020
Keysight Technologies, Inc. (a)	25		3,934
Mettler-Toledo International, Inc. (a)	3		3,252
TE Connectivity Ltd.	37		4,083
		$	54,940
Energy — Alternate Sources — 0.09%
Enphase Energy, Inc. (a)	17		4,717
Engineering & Construction — 0.07%
Jacobs Solutions, Inc.	37		4,014
Entertainment — 0.06%
Live Nation Entertainment, Inc. (a)	43		3,270
Environmental Control — 0.60%
Republic Services, Inc.	98		13,332
Waste Management, Inc.	119		19,065
		$	32,397
Food — 2.80%
Campbell Soup Co.	220		10,366
Conagra Brands, Inc.	247		8,060
General Mills, Inc.	223		17,084
Hershey Co.	66		14,551
Hormel Foods Corp.	174		7,907
J M Smucker Co.	59		8,107
Kellogg Co.	169		11,773
Kraft Heinz Co.	281		9,371
Kroger Co.	187		8,181
Lamb Weston Holdings, Inc.	100		7,738
McCormick & Co., Inc.	111		7,911
Mondelez International, Inc., Class A	276		15,133
Sysco Corp.	203		14,354
Tyson Foods, Inc., Class A	174		11,472
		$	152,008
Gas — 0.26%
Atmos Energy Corp.	73		7,435

See accompanying notes.

67

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Gas (continued)
NiSource, Inc.	270	$	6,801
		$	14,236
Hand/Machine Tools — 0.19%
Snap-on, Inc.	50		10,068
Healthcare — Products — 2.49%
Abbott Laboratories	273		26,415
Align Technology, Inc. (a)	14		2,900
Bio-Techne Corp.	10		2,840
Boston Scientific Corp. (a)	330		12,781
Danaher Corp.	44		11,365
Edwards Lifesciences Corp. (a)	60		4,958
Henry Schein, Inc. (a)	105		6,906
Hologic, Inc. (a)	66		4,258
IDEXX Laboratories, Inc. (a)	12		3,910
Intuitive Surgical, Inc. (a)	31		5,811
Medtronic PLC	131		10,578
ResMed, Inc.	44		9,605
Stryker Corp.	29		5,874
Teleflex, Inc.	13		2,619
Thermo Fisher Scientific, Inc.	26		13,187
Waters Corp. (a)	12		3,234
West Pharmaceutical Services, Inc.	13		3,199
Zimmer Biomet Holdings, Inc.	44		4,600
		$	135,040
Healthcare — Services — 3.34%
Catalent, Inc. (a)	37		2,677
Centene Corp. (a)	127		9,882
Charles River Laboratories International, Inc. (a)	15		2,952
DaVita, Inc. (a)	30		2,483
Elevance Health, Inc.	61		27,709
HCA Healthcare, Inc.	23		4,227
Humana, Inc.	40		19,408
IQVIA Holdings, Inc. (a)	22		3,985
Laboratory Corp. of America Holdings	37		7,578
Molina Healthcare, Inc. (a)	26		8,576
Quest Diagnostics, Inc.	60		7,361
UnitedHealth Group, Inc.	167		84,342
		$	181,180
Home Builders — 0.25%
DR Horton, Inc.	52		3,502
Lennar Corp., Class A	46		3,429
NVR, Inc. (a)	1		3,987
PulteGroup, Inc.	75		2,813
		$	13,731
Household Products — 1.30%
Colgate-Palmolive Co.	265		18,616
Estee Lauder Cos., Inc., Class A	23		4,966
Procter & Gamble Co.	373		47,091
		$	70,673
Household Products/Wares — 0.61%
Avery Dennison Corp.	19		3,091
Church & Dwight Co., Inc.	158		11,288

See accompanying notes.

68

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Household Products/Wares (continued)
Clorox Co.	28	$	3,595
Kimberly-Clark Corp.	132		14,855
		$	32,829
Insurance — 4.84%
Aflac, Inc.	178		10,003
Allstate Corp.	83		10,336
American International Group, Inc.	98		4,653
Aon PLC, Class A	47		12,590
Arthur J Gallagher & Co.	86		14,725
Assurant, Inc.	47		6,828
Berkshire Hathaway, Inc., Class B (a)	239		63,818
Brown & Brown, Inc.	185		11,189
Chubb Ltd.	85		15,460
Everest Re Group Ltd.	27		7,086
Globe Life, Inc.	102		10,169
Hartford Financial Services Group, Inc.	137		8,486
Loews Corp.	142		7,077
Marsh & McLennan Cos., Inc.	99		14,780
MetLife, Inc.	181		11,001
Progressive Corp.	124		14,410
Prudential Financial, Inc.	115		9,865
Travelers Cos., Inc.	69		10,571
W R Berkley Corp.	168		10,849
Willis Towers Watson PLC	41		8,238
		$	262,134
Internet — 8.27%
Alphabet, Inc., Class A (a)	1,074		102,728
Alphabet, Inc., Class C (a)	961		92,400
Amazon.com, Inc. (a)	1,586		179,218
CDW Corp.	50		7,804
F5, Inc. (a)	20		2,895
Meta Platforms, Inc., Class A (a)	406		55,086
Netflix, Inc. (a)	34		8,005
		$	448,136
Iron & Steel — 0.15%
Nucor Corp.	75		8,024
Lodging — 0.16%
Las Vegas Sands Corp. (a)	97		3,639
Marriott International, Inc., Class A	35		4,905
		$	8,544
Machinery — Diversified — 0.91%
Deere & Co.	22		7,345
Dover Corp.	65		7,578
IDEX Corp.	56		11,192
Nordson Corp.	33		7,005
Otis Worldwide Corp.	146		9,315
Westinghouse Air Brake Technologies Corp.	84		6,833
		$	49,268
Media — 0.67%
Charter Communications, Inc., Class A (a)	12		3,640
Comcast Corp., Class A	307		9,004
FactSet Research Systems, Inc.	26		10,403

See accompanying notes.

69

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Media (continued)
Fox Corp., Class A	226	$	6,934
Fox Corp., Class B	220		6,270
		$	36,251
Miscellaneous Manufacturers — 0.70%
3M Co.	118		13,039
A O Smith Corp.	55		2,672
Eaton Corp. PLC	52		6,935
Illinois Tool Works, Inc.	37		6,684
Textron, Inc.	60		3,495
Trane Technologies PLC	37		5,358
		$	38,183
Oil & Gas — 3.50%
APA Corp.	93		3,180
Chevron Corp.	321		46,118
ConocoPhillips	95		9,722
Coterra Energy, Inc.	278		7,261
Devon Energy Corp.	81		4,871
Diamondback Energy, Inc.	61		7,348
EOG Resources, Inc.	57		6,369
Exxon Mobil Corp.	743		64,871
Hess Corp.	40		4,360
Marathon Oil Corp.	153		3,455
Marathon Petroleum Corp.	59		5,860
Occidental Petroleum Corp.	87		5,346
Phillips 66	64		5,166
Pioneer Natural Resources Co.	49		10,610
Valero Energy Corp.	50		5,342
		$	189,879
Oil & Gas Services — 0.25%
Baker Hughes Co.	183		3,836
Halliburton Co.	157		3,865
Schlumberger NV	156		5,600
		$	13,301
Packaging & Containers — 0.48%
Amcor PLC	1,021		10,955
Ball Corp.	60		2,899
Packaging Corp. of America	57		6,401
Sealed Air Corp.	129		5,742
		$	25,997
Pharmaceuticals — 8.10%
AbbVie, Inc.	376		50,463
AmerisourceBergen Corp.	90		12,180
Becton Dickinson and Co.	60		13,370
Bristol-Myers Squibb Co.	503		35,758
Cardinal Health, Inc.	128		8,535
Cigna Corp.	85		23,585
CVS Health Corp.	226		21,554
Eli Lilly & Co.	169		54,646
Johnson & Johnson	521		85,111
McKesson Corp.	51		17,333
Merck & Co., Inc.	552		47,538
Organon & Co.	132		3,089

See accompanying notes.

70

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Pharmaceuticals (continued)
Pfizer, Inc.	1,191	$	52,118
Zoetis, Inc.	95		14,087
		$	439,367
Pipelines — 0.44%
Kinder Morgan, Inc.	601		10,001
ONEOK, Inc.	75		3,843
Williams Cos., Inc.	351		10,049
		$	23,893
Real Estate — 0.14%
CBRE Group, Inc., Class A (a)	115		7,764
REITs — 3.90%
Alexandria Real Estate Equities, Inc.	32		4,486
American Tower Corp.	81		17,391
AvalonBay Communities, Inc.	49		9,025
Boston Properties, Inc.	49		3,673
Camden Property Trust	58		6,928
Crown Castle, Inc.	89		12,865
Digital Realty Trust, Inc.	37		3,670
Duke Realty Corp.	78		3,760
Equity Residential	129		8,671
Essex Property Trust, Inc.	17		4,118
Extra Space Storage, Inc.	72		12,435
Federal Realty Investment Trust	72		6,489
Healthpeak Properties, Inc.	165		3,782
Host Hotels & Resorts, Inc.	211		3,351
Invitation Homes, Inc.	129		4,356
Iron Mountain, Inc.	131		5,760
Kimco Realty Corp.	382		7,033
Mid-America Apartment Communities, Inc.	49		7,598
Prologis, Inc.	61		6,198
Public Storage	56		16,397
Realty Income Corp.	247		14,375
Regency Centers Corp.	126		6,785
SBA Communications Corp.	14		3,985
Simon Property Group, Inc.	48		4,308
UDR, Inc.	94		3,921
Ventas, Inc.	181		7,271
VICI Properties, Inc.	309		9,224
Welltower, Inc.	78		5,017
Weyerhaeuser Co.	298		8,511
		$	211,383
Retail — 4.59%
Advance Auto Parts, Inc.	22		3,440
AutoZone, Inc. (a)	8		17,135
Chipotle Mexican Grill, Inc. (a)	3		4,508
Costco Wholesale Corp.	58		27,392
Darden Restaurants, Inc.	26		3,284
Dollar General Corp.	76		18,229
Dollar Tree, Inc. (a)	33		4,491
Domino's Pizza, Inc.	21		6,514
Genuine Parts Co.	82		12,244
Home Depot, Inc.	157		43,323
Lowe's Cos., Inc.	47		8,827
McDonald's Corp.	117		26,997

See accompanying notes.

71

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Retail (continued)
O'Reilly Automotive, Inc. (a)	24	$	16,880
Target Corp.	40		5,936
Tractor Supply Co.	19		3,532
Ulta Beauty, Inc. (a)	19		7,623
Walgreens Boots Alliance, Inc.	146		4,584
Walmart, Inc.	221		28,664
Yum! Brands, Inc.	48		5,104
		$	248,707
Semiconductors — 2.22%
Applied Materials, Inc.	74		6,063
Broadcom, Inc.	26		11,544
KLA Corp.	15		4,540
Lam Research Corp.	13		4,758
Microchip Technology, Inc.	67		4,089
Monolithic Power Systems, Inc.	8		2,907
NVIDIA Corp.	446		54,140
ON Semiconductor Corp. (a)	127		7,916
QUALCOMM, Inc.	80		9,038
Skyworks Solutions, Inc.	33		2,814
Teradyne, Inc.	38		2,856
Texas Instruments, Inc.	64		9,906
		$	120,571
Shipbuilding — 0.13%
Huntington Ingalls Industries, Inc.	32		7,088
Software — 8.46%
Activision Blizzard, Inc.	172		12,787
Adobe, Inc. (a)	33		9,082
Akamai Technologies, Inc. (a)	85		6,827
ANSYS, Inc. (a)	15		3,326
Broadridge Financial Solutions, Inc.	75		10,824
Cadence Design Systems, Inc. (a)	30		4,903
Citrix Systems, Inc. (a)	77		8,000
Electronic Arts, Inc.	45		5,207
Fidelity National Information Services, Inc.	62		4,685
Fiserv, Inc. (a)	199		18,620
Intuit, Inc.	21		8,134
Jack Henry & Associates, Inc.	59		10,754
Microsoft Corp.	1,334		310,689
MSCI, Inc.	10		4,218
Oracle Corp.	155		9,466
Paychex, Inc.	130		14,587
Paycom Software, Inc. (a)	10		3,300
PTC, Inc. (a)	27		2,824
Roper Technologies, Inc.	16		5,754
Synopsys, Inc. (a)	16		4,888
		$	458,875
Telecommunications — 2.14%
Arista Networks, Inc. (a)	74		8,354
AT&T, Inc.	1,266		19,421
Cisco Systems, Inc.	648		25,920
Corning, Inc.	118		3,424
Juniper Networks, Inc.	269		7,026
Motorola Solutions, Inc.	47		10,527
T-Mobile U.S., Inc. (a)	120		16,100

See accompanying notes.

72

		Schedule of Investments
	Principal U.S. Large-Cap Adaptive Multi-Factor ETF
		September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held			Value
Telecommunications (continued)
Verizon Communications, Inc.		662		$	25,136
				$	115,908
Toys, Games & Hobbies — 0.11%
Hasbro, Inc.		92			6,203
Transportation — 1.81%
CH Robinson Worldwide, Inc.		67			6,453
CSX Corp.		481			12,814
Expeditors International of Washington, Inc.		35			3,091
JB Hunt Transport Services, Inc.		42			6,570
Norfolk Southern Corp.		31			6,499
Old Dominion Freight Line, Inc.		15			3,732
Union Pacific Corp.		153			29,807
United Parcel Service, Inc., Class B		180			29,077
				$	98,043
Water — 0.15%
American Water Works Co., Inc.		61			7,940
TOTAL COMMON STOCKS				$	5,401,878
INVESTMENT COMPANIES — 0.28%		Shares Held			Value
Money Market Fund — 0.28%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (b)		15,201			15,201
TOTAL INVESTMENT COMPANIES				$	15,201
Total Investments				$	5,417,079
Other Assets and Liabilities — 0.08%					4,496
Total Net Assets — 100.00%				$	5,421,575
(a)	Non-income producing security.
(b)	Current yield shown is as of period end.
	Portfolio Summary (unaudited)
Sector		Percent
Consumer, Non-cyclical		26.18	%
Technology		19.04	%
Financial		14.75	%
Communications		11.21	%
Consumer, Cyclical		8.81	%
Industrial		8.74	%
Utilities		5.11	%
Energy		4.28	%
Basic Materials		1.52	%
Money Market Fund		0.28	%
Other Assets and Liabilities		0.08	%
TOTAL NET ASSETS		100.00	%

See accompanying notes. 73

	Schedule of Investments
	Principal U.S. Mega-Cap ETF
	September 30, 2022 (unaudited)
COMMON STOCKS — 99.66%		Shares Held		Value
Auto Manufacturers — 2.91%
Tesla, Inc. (a)		109,717	$	29,102,434
Banks — 6.41%
Bank of America Corp.		710,992		21,471,958
JPMorgan Chase & Co.		287,870		30,082,415
Wells Fargo & Co.		311,636		12,534,000
			$	64,088,373
Beverages — 3.66%
Coca-Cola Co.		406,737		22,785,407
PepsiCo, Inc.		84,652		13,820,285
			$	36,605,692
Chemicals — 2.08%
Linde PLC		77,174		20,805,339
Computers — 9.40%
Accenture PLC, Class A		84,377		21,710,202
Apple, Inc.		523,455		72,341,481
			$	94,051,683
Diversified Financial Services — 6.10%
Mastercard, Inc., Class A		104,715		29,774,663
Visa, Inc., Class A		176,201		31,302,108
			$	61,076,771
Healthcare — Products — 8.08%
Abbott Laboratories		219,681		21,256,334
Danaher Corp.		140,257		36,226,980
Thermo Fisher Scientific, Inc.		46,105		23,383,995
			$	80,867,309
Healthcare — Services — 2.66%
UnitedHealth Group, Inc.		52,761		26,646,416
Household Products — 2.21%
Procter & Gamble Co.		175,544		22,162,430
Insurance — 2.20%
Berkshire Hathaway, Inc., Class B (a)		82,358		21,991,233
Internet — 8.15%
Alphabet, Inc., Class A (a)		326,718		31,250,577
Amazon.com, Inc. (a)		209,589		23,683,557
Meta Platforms, Inc., Class A (a)		196,401		26,647,687
			$	81,581,821
Media — 2.96%
Comcast Corp., Class A		596,418		17,492,940
Walt Disney Co. (a)		128,293		12,101,879
			$	29,594,819
Oil & Gas — 4.35%
Chevron Corp.		144,881		20,815,053
Exxon Mobil Corp.		259,671		22,671,875
			$	43,486,928
Pharmaceuticals — 11.73%
AbbVie, Inc.		174,041		23,358,043

See accompanying notes.

74

	Schedule of Investments
	Principal U.S. Mega-Cap ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Pharmaceuticals (continued)
Eli Lilly & Co.		46,306	$	14,973,045
Johnson & Johnson		145,209		23,721,342
Merck & Co., Inc.		284,915		24,536,880
Pfizer, Inc.		704,308		30,820,518
			$	117,409,828
Retail — 6.55%
Costco Wholesale Corp.		54,027		25,515,331
Home Depot, Inc.		45,759		12,626,738
McDonald's Corp.		56,225		12,973,357
Walmart, Inc.		111,330		14,439,501
			$	65,554,927
Semiconductors — 7.52%
Advanced Micro Devices, Inc. (a)		352,485		22,333,450
Broadcom, Inc.		45,677		20,281,045
Intel Corp.		321,724		8,290,827
NVIDIA Corp.		200,156		24,296,937
			$	75,202,259
Software — 9.37%
Adobe, Inc. (a)		87,186		23,993,587
Microsoft Corp.		253,055		58,936,510
salesforce, Inc. (a)		75,455		10,853,447
			$	93,783,544
Telecommunications — 3.32%
Cisco Systems, Inc.		568,637		22,745,480
Verizon Communications, Inc.		274,690		10,429,979
			$	33,175,459
TOTAL COMMON STOCKS			$	997,187,265
INVESTMENT COMPANIES — 0.29%		Shares Held		Value
Money Market Fund — 0.29%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (b)		2,867,394	$	2,867,394
TOTAL INVESTMENT COMPANIES			$	2,867,394
Total Investments			$	1,000,054,659
Other Assets and Liabilities — 0.05%				548,396
Total Net Assets — 100.00%			$	1,000,603,055
(a)	Non-income producing security.
(b)	Current yield shown is as of period end.

See accompanying notes. 75

     Schedule of Investments Principal U.S. Mega-Cap ETF September 30, 2022 (unaudited)

Portfolio Summary (unaudited)

Sector	Percent
Consumer, Non-cyclical	28.35	%
Technology	26.29	%
Financial	14.71	%
Communications	14.43	%
Consumer, Cyclical	9.46	%
Energy	4.34	%
Basic Materials	2.08	%
Money Market Fund	0.29	%
Other Assets and Liabilities	0.05	%
TOTAL NET ASSETS	100.00	%

See accompanying notes.

76

Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS — 99.64%	Shares Held		Value
Aerospace & Defense — 1.81%
AAR Corp. (a)	323	$	11,570
Aerojet Rocketdyne Holdings, Inc. (a)	694		27,753
AeroVironment, Inc. (a)	78		6,502
Barnes Group, Inc.	259		7,480
Kaman Corp.	345		9,636
Moog, Inc., Class A	312		21,949
National Presto Industries, Inc.	122		7,936
		$	92,826
Agriculture — 0.80%
Andersons, Inc.	291		9,030
Fresh Del Monte Produce, Inc.	402		9,342
Universal Corp.	244		11,234
Vector Group Ltd.	1,293		11,391
		$	40,997
Apparel — 0.33%
Oxford Industries, Inc.	121		10,863
Steven Madden Ltd.	228		6,081
		$	16,944
Auto Manufacturers — 0.09%
Wabash National Corp.	285		4,435
Auto Parts & Equipment — 1.34%
American Axle & Manufacturing Holdings, Inc. (a)	559		3,818
Dorman Products, Inc. (a)	290		23,815
Methode Electronics, Inc.	329		12,222
Motorcar Parts of America, Inc. (a)	243		3,698
Standard Motor Products, Inc.	387		12,578
Titan International, Inc. (a)	617		7,490
XPEL, Inc. (a)	77		4,962
		$	68,583
Banks — 16.03%
Allegiance Bancshares, Inc.	329		13,696
Ameris Bancorp	612		27,363
BancFirst Corp.	208		18,610
Bancorp, Inc. (a)	217		4,770
BankUnited, Inc.	295		10,080
Banner Corp.	366		21,623
Central Pacific Financial Corp.	587		12,145
City Holding Co.	204		18,093
Columbia Banking System, Inc.	816		23,574
Community Bank System, Inc.	341		20,487
Customers Bancorp, Inc. (a)	137		4,039
CVB Financial Corp.	1,196		30,283
Dime Community Bancshares, Inc.	502		14,699
Eagle Bancorp, Inc.	275		12,326
FB Financial Corp.	465		17,768
First BanCorp	1,858		25,417
First Bancorp/Southern Pines NC	321		11,742
First Commonwealth Financial Corp.	1,267		16,268
First Financial Bancorp	1,039		21,902
First Hawaiian, Inc.	821		20,221
Flagstar Bancorp, Inc.	404		13,494
Hanmi Financial Corp.	568		13,450
Heritage Financial Corp.	558		14,770

See accompanying notes.

77

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Banks (continued)
Hilltop Holdings, Inc.	255	$	6,337
HomeStreet, Inc.	153		4,408
Hope Bancorp, Inc.	1,388		17,544
Independent Bank Corp.	411		30,632
Independent Bank Group, Inc.	364		22,346
Lakeland Financial Corp.	284		20,678
National Bank Holdings Corp., Class A	305		11,282
NBT Bancorp, Inc.	504		19,127
OFG Bancorp	638		16,033
Park National Corp.	165		20,539
Pathward Financial, Inc.	134		4,417
Preferred Bank	221		14,416
Renasant Corp.	641		20,050
S&T Bancorp, Inc.	545		15,974
Seacoast Banking Corp. of Florida	688		20,798
ServisFirst Bancshares, Inc.	424		33,920
Simmons First National Corp., Class A	848		18,478
Southside Bancshares, Inc.	434		15,346
Tompkins Financial Corp.	208		15,105
Triumph Bancorp, Inc. (a)	86		4,674
TrustCo Bank Corp.	281		8,829
Trustmark Corp.	477		14,611
United Community Banks, Inc.	955		31,610
Veritex Holdings, Inc.	446		11,859
Walker & Dunlop, Inc.	202		16,913
Westamerica BanCorp	347		18,145
		$	820,891
Beverages — 0.57%
MGP Ingredients, Inc.	184		19,534
National Beverage Corp.	250		9,635
		$	29,169
Biotechnology — 1.00%
ANI Pharmaceuticals, Inc. (a)	108		3,471
Cytokinetics, Inc. (a)	599		29,022
Dynavax Technologies Corp. (a)	446		4,656
Innoviva, Inc. (a)	778		9,033
Vir Biotechnology, Inc. (a)	269		5,186
		$	51,368
Building Materials — 0.35%
SPX Technologies, Inc. (a)	327		18,057
Chemicals — 3.33%
AdvanSix, Inc.	271		8,699
American Vanguard Corp.	389		7,274
Balchem Corp.	193		23,465
Hawkins, Inc.	362		14,114
HB Fuller Co.	496		29,810
Innospec, Inc.	266		22,788
Koppers Holdings, Inc.	159		3,304
Minerals Technologies, Inc.	265		13,094
Quaker Chemical Corp.	43		6,208
Rogers Corp. (a)	110		26,607
Stepan Co.	162		15,175
		$	170,538

See accompanying notes.

78

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Coal — 0.43%
CONSOL Energy, Inc.	111	$	7,139
SunCoke Energy, Inc.	643		3,736
Warrior Met Coal, Inc.	391		11,120
		$	21,995
Commercial Services — 4.29%
ABM Industries, Inc.	661		25,270
Adtalem Global Education, Inc. (a)	377		13,742
Alarm.com Holdings, Inc. (a)	319		20,690
AMN Healthcare Services, Inc. (a)	107		11,338
CoreCivic, Inc. (a)	528		4,667
CorVel Corp. (a)	82		11,351
Cross Country Healthcare, Inc. (a)	325		9,220
EVERTEC, Inc.	478		14,985
Forrester Research, Inc. (a)	214		7,706
Green Dot Corp., Class A (a)	214		4,062
Heidrick & Struggles International, Inc.	321		8,343
Kelly Services, Inc., Class A	270		3,669
Korn Ferry	368		17,278
Medifast, Inc.	41		4,443
Monro, Inc.	293		12,734
Perdoceo Education Corp. (a)	921		9,486
Resources Connection, Inc.	688		12,432
Strategic Education, Inc.	203		12,466
Stride, Inc. (a)	290		12,189
Viad Corp. (a)	120		3,790
		$	219,861
Computers — 1.48%
ExlService Holdings, Inc. (a)	264		38,903
Insight Enterprises, Inc. (a)	209		17,224
NetScout Systems, Inc. (a)	502		15,722
TTEC Holdings, Inc.	87		3,855
		$	75,704
Construction Materials — 2.17%
AAON, Inc.	302		16,272
Apogee Enterprises, Inc.	265		10,128
Boise Cascade Co.	243		14,449
Gibraltar Industries, Inc. (a)	120		4,911
Griffon Corp.	352		10,391
PGT Innovations, Inc. (a)	833		17,460
UFP Industries, Inc.	520		37,523
		$	111,134
Distribution/Wholesale — 0.50%
KAR Auction Services, Inc. (a)	456		5,093
Resideo Technologies, Inc. (a)	402		7,662
ScanSource, Inc. (a)	295		7,791
Veritiv Corp. (a)	53		5,182
		$	25,728
Diversified Financial Services — 2.16%
Blucora, Inc. (a)	555		10,734
Brightsphere Investment Group, Inc.	516		7,694
Encore Capital Group, Inc. (a)	202		9,187
Enova International, Inc. (a)	151		4,420

See accompanying notes.

79

Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Diversified Financial Services (continued)
EZCORP, Inc., Class A (a)	1,059	$	8,165
LendingTree, Inc. (a)	99		2,362
Mr Cooper Group, Inc. (a)	459		18,589
Piper Sandler Cos.	120		12,569
PRA Group, Inc. (a)	347		11,402
StoneX Group, Inc. (a)	156		12,939
Virtus Investment Partners, Inc.	27		4,307
WisdomTree Investments, Inc.	1,749		8,185
		$	110,553
Electric — 0.63%
Avista Corp.	496		18,377
Unitil Corp.	295		13,703
		$	32,080
Electrical Components & Equipment — 0.40%
Encore Wire Corp.	120		13,865
Insteel Industries, Inc.	130		3,449
Powell Industries, Inc.	146		3,077
		$	20,391
Electronics — 2.55%
Advanced Energy Industries, Inc.	102		7,896
Badger Meter, Inc.	201		18,570
Benchmark Electronics, Inc.	581		14,397
Brady Corp., Class A	349		14,564
CTS Corp.	296		12,328
Knowles Corp. (a)	509		6,195
OSI Systems, Inc. (a)	223		16,069
Plexus Corp. (a)	191		16,724
Sanmina Corp. (a)	405		18,663
TTM Technologies, Inc. (a)	400		5,272
		$	130,678
Energy — Alternate Sources — 0.20%
FutureFuel Corp.	511		3,086
REX American Resources Corp. (a)	255		7,120
		$	10,206
Engineering & Construction — 2.49%
Arcosa, Inc.	476		27,218
Comfort Systems USA, Inc.	323		31,438
Exponent, Inc.	299		26,213
Frontdoor, Inc. (a)	268		5,464
Granite Construction, Inc.	244		6,195
MYR Group, Inc. (a)	145		12,286
NV5 Global, Inc. (a)	151		18,697
		$	127,511
Entertainment — 0.18%
Cinemark Holdings, Inc. (a)	421		5,098
Monarch Casino & Resort, Inc. (a)	69		3,874
		$	8,972
Food — 3.20%
B&G Foods, Inc.	374		6,167
Cal-Maine Foods, Inc.	290		16,121

See accompanying notes.

80

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Food (continued)
Calavo Growers, Inc.	118	$	3,746
Chefs' Warehouse, Inc. (a)	151		4,374
Hostess Brands, Inc. (a)	1,262		29,329
J & J Snack Foods Corp.	116		15,019
John B Sanfilippo & Son, Inc.	70		5,301
Seneca Foods Corp., Class A (a)	70		3,531
Simply Good Foods Co. (a)	601		19,226
SpartanNash Co.	543		15,758
Tootsie Roll Industries, Inc.	274		9,119
TreeHouse Foods, Inc. (a)	371		15,738
United Natural Foods, Inc. (a)	598		20,553
		$	163,982
Forest Products & Paper — 0.31%
Clearwater Paper Corp. (a)	107		4,023
Mercer International, Inc.	565		6,949
Sylvamo Corp.	144		4,882
		$	15,854
Gas — 1.34%
Chesapeake Utilities Corp.	130		15,001
Northwest Natural Holding Co.	422		18,306
South Jersey Industries, Inc.	1,057		35,325
		$	68,632
Hand/Machine Tools — 0.62%
Enerpac Tool Group Corp.	639		11,394
Franklin Electric Co., Inc.	251		20,509
		$	31,903
Healthcare — Products — 2.34%
Artivion, Inc. (a)	216		2,990
Avanos Medical, Inc. (a)	490		10,672
Cutera, Inc. (a)	95		4,332
Glaukos Corp. (a)	140		7,454
Integer Holdings Corp. (a)	141		8,774
Lantheus Holdings, Inc. (a)	334		23,490
LeMaitre Vascular, Inc.	211		10,694
Meridian Bioscience, Inc. (a)	576		18,161
Merit Medical Systems, Inc. (a)	364		20,570
Orthofix Medical, Inc. (a)	220		4,204
Varex Imaging Corp. (a)	266		5,623
Zynex, Inc.	313		2,839
		$	119,803
Healthcare — Services — 1.31%
Addus HomeCare Corp. (a)	205		19,524
Ensign Group, Inc.	462		36,729
Select Medical Holdings Corp.	293		6,476
U.S. Physical Therapy, Inc.	58		4,409
		$	67,138
Home Builders — 1.31%
Cavco Industries, Inc. (a)	58		11,934
Century Communities, Inc.	111		4,749
Green Brick Partners, Inc. (a)	162		3,464
Installed Building Products, Inc.	75		6,074

See accompanying notes.

81

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Home Builders (continued)
LCI Industries	72	$	7,305
LGI Homes, Inc. (a)	69		5,615
M/I Homes, Inc. (a)	118		4,275
MDC Holdings, Inc.	196		5,374
Meritage Homes Corp. (a)	104		7,308
Tri Pointe Homes, Inc. (a)	348		5,258
Winnebago Industries, Inc.	105		5,587
		$	66,943
Home Furnishings — 0.23%
Ethan Allen Interiors, Inc.	546		11,542
Household Products — 0.88%
Edgewell Personal Care Co.	407		15,222
elf Beauty, Inc. (a)	327		12,302
Inter Parfums, Inc.	234		17,657
		$	45,181
Household Products/Wares — 0.77%
Central Garden & Pet Co., Class A (a)	361		12,332
Central Garden & Pet Co. (a)	212		7,640
Quanex Building Products Corp.	677		12,294
WD-40 Co.	40		7,030
		$	39,296
Insurance — 3.58%
Ambac Financial Group, Inc. (a)	286		3,646
American Equity Investment Life Holding Co.	416		15,513
AMERISAFE, Inc.	224		10,468
Assured Guaranty Ltd.	406		19,671
Employers Holdings, Inc.	300		10,347
Genworth Financial, Inc., Class A (a)	3,928		13,748
Horace Mann Educators Corp.	366		12,916
James River Group Holdings Ltd.	246		5,611
Mercury General Corp.	182		5,172
NMI Holdings, Inc., Class A (a)	969		19,739
Palomar Holdings, Inc. (a)	166		13,898
ProAssurance Corp.	566		11,043
Safety Insurance Group, Inc.	144		11,745
SiriusPoint Ltd. (a)	990		4,900
Stewart Information Services Corp.	246		10,735
United Fire Group, Inc.	262		7,527
Universal Insurance Holdings, Inc.	687		6,767
		$	183,446
Internet — 1.05%
Cars.com, Inc. (a)	388		4,462
Cogent Communications Holdings, Inc.	311		16,222
ePlus, Inc. (a)	227		9,430
HealthStream, Inc. (a)	230		4,890
Perficient, Inc. (a)	105		6,827
Shutterstock, Inc.	91		4,565
Yelp, Inc. (a)	218		7,392
		$	53,788
Iron & Steel — 0.28%
ATI, Inc. (a)	344		9,154

See accompanying notes.

82

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Iron & Steel (continued)
Carpenter Technology Corp.	173	$	5,387
		$	14,541
Lodging — 0.15%
Marcus Corp.	535		7,431
Machinery — Diversified — 1.98%
Alamo Group, Inc.	99		12,105
Albany International Corp., Class A	311		24,516
Applied Industrial Technologies, Inc.	336		34,534
DXP Enterprises, Inc. (a)	144		3,410
Ichor Holdings Ltd. (a)	147		3,559
Lindsay Corp.	52		7,450
Tennant Co.	277		15,667
		$	101,241
Media — 0.41%
AMC Networks, Inc., Class A (a)	159		3,228
Scholastic Corp.	292		8,982
Thryv Holdings, Inc. (a)	393		8,972
		$	21,182
Metal Fabrication & Hardware — 1.29%
AZZ, Inc.	156		5,696
Mueller Industries, Inc.	520		30,909
Olympic Steel, Inc.	258		5,885
Standex International Corp.	187		15,268
TimkenSteel Corp. (a)	275		4,122
Tredegar Corp.	436		4,116
		$	65,996
Mining — 0.73%
Century Aluminum Co. (a)	451		2,381
Livent Corp. (a)	1,140		34,941
		$	37,322
Miscellaneous Manufacturers — 2.96%
EnPro Industries, Inc.	238		20,225
ESCO Technologies, Inc.	204		14,982
Fabrinet (a)	96		9,163
Federal Signal Corp.	427		15,936
Haynes International, Inc.	102		3,582
Hillenbrand, Inc.	678		24,896
John Bean Technologies Corp.	89		7,654
Materion Corp.	251		20,080
Myers Industries, Inc.	753		12,402
Park Aerospace Corp.	383		4,229
Sturm Ruger & Co., Inc.	205		10,412
Trinity Industries, Inc.	366		7,814
		$	151,375
Office Furnishings — 0.18%
HNI Corp.	228		6,045
Interface, Inc.	373		3,353
		$	9,398
Oil & Gas — 2.17%
Callon Petroleum Co. (a)	329		11,518

See accompanying notes.

83

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Oil & Gas (continued)
Civitas Resources, Inc.	293	$	16,815
Helmerich & Payne, Inc.	268		9,908
Laredo Petroleum, Inc. (a)	77		4,840
Nabors Industries Ltd. (a)	41		4,160
Par Pacific Holdings, Inc. (a)	280		4,595
Patterson-UTI Energy, Inc.	641		7,487
PBF Energy, Inc., Class A (a)	308		10,829
Ranger Oil Corp., Class A	222		6,982
SM Energy Co.	781		29,373
Talos Energy, Inc. (a)	283		4,712
		$	111,219
Oil & Gas Services — 0.62%
Archrock, Inc.	670		4,302
Dril-Quip, Inc. (a)	200		3,904
Helix Energy Solutions Group, Inc. (a)	931		3,594
NOW, Inc. (a)	475		4,774
Oil States International, Inc. (a)	782		3,042
ProPetro Holding Corp. (a)	506		4,073
RPC, Inc.	552		3,825
U.S. Silica Holdings, Inc. (a)	392		4,292
		$	31,806
Packaging & Containers — 0.23%
Matthews International Corp., Class A	227		5,087
O-I Glass, Inc. (a)	520		6,734
		$	11,821
Pharmaceuticals — 2.63%
AdaptHealth Corp. (a)	270		5,071
Amphastar Pharmaceuticals, Inc. (a)	337		9,470
Anika Therapeutics, Inc. (a)	195		4,641
Catalyst Pharmaceuticals, Inc. (a)	399		5,119
Corcept Therapeutics, Inc. (a)	575		14,743
Covetrus, Inc. (a)	801		16,725
Embecta Corp.	202		5,816
Enanta Pharmaceuticals, Inc. (a)	89		4,616
Harmony Biosciences Holdings, Inc. (a)	123		5,448
Ironwood Pharmaceuticals, Inc. (a)	679		7,034
Pacira BioSciences, Inc. (a)	183		9,734
Phibro Animal Health Corp., Class A	460		6,113
Prestige Consumer Healthcare, Inc. (a)	341		16,992
Supernus Pharmaceuticals, Inc. (a)	426		14,420
USANA Health Sciences, Inc. (a)	160		8,968
		$	134,910
Real Estate — 0.75%
Alexander & Baldwin, Inc.	700		11,606
Marcus & Millichap, Inc.	280		9,178
RE/MAX Holdings, Inc., Class A	387		7,318
St. Joe Co.	328		10,506
		$	38,608
REITs — 9.71%
Acadia Realty Trust	852		10,752
Agree Realty Corp.	636		42,981
American Assets Trust, Inc.	264		6,790

See accompanying notes.

84

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
REITs (continued)
Apollo Commercial Real Estate Finance, Inc.	649	$	5,387
Armada Hoffler Properties, Inc.	1,158		12,020
ARMOUR Residential REIT, Inc.	1,523		7,417
Brandywine Realty Trust	876		5,913
CareTrust REIT, Inc.	757		13,709
Centerspace	87		5,857
Chatham Lodging Trust (a)	746		7,363
Community Healthcare Trust, Inc.	281		9,203
DiamondRock Hospitality Co.	730		5,482
Easterly Government Properties, Inc.	771		12,159
Ellington Financial, Inc.	709		8,061
Essential Properties Realty Trust, Inc.	923		17,952
Four Corners Property Trust, Inc.	873		21,118
Franklin BSP Realty Trust, Inc.	525		5,654
Franklin Street Properties Corp.	1,434		3,771
GEO Group, Inc. (a)	599		4,612
Getty Realty Corp.	574		15,435
Global Net Lease, Inc.	958		10,203
Granite Point Mortgage Trust, Inc.	563		3,626
Hersha Hospitality Trust, Class A	367		2,929
Hudson Pacific Properties, Inc.	608		6,658
Innovative Industrial Properties, Inc.	85		7,523
KKR Real Estate Finance Trust, Inc.	577		9,376
LTC Properties, Inc.	335		12,546
LXP Industrial Trust	1,076		9,856
New York Mortgage Trust, Inc.	2,260		5,288
NexPoint Residential Trust, Inc.	128		5,915
Office Properties Income Trust	594		8,346
Orion Office REIT, Inc.	511		4,471
PennyMac Mortgage Investment Trust	477		5,619
Ready Capital Corp.	934		9,471
Redwood Trust, Inc.	815		4,678
Retail Opportunity Investments Corp.	1,392		19,154
RPT Realty	612		4,627
Safehold, Inc.	103		2,725
Saul Centers, Inc.	304		11,400
SITE Centers Corp.	754		8,075
Summit Hotel Properties, Inc.	584		3,925
Sunstone Hotel Investors, Inc.	1,535		14,460
Tanger Factory Outlet Centers, Inc.	896		12,257
Two Harbors Investment Corp.	2,899		9,625
Uniti Group, Inc.	1,773		12,322
Universal Health Realty Income Trust	273		11,796
Urban Edge Properties	1,372		18,303
Urstadt Biddle Properties, Inc., Class A	537		8,329
Veris Residential, Inc. (a)	832		9,460
Washington Real Estate Investment Trust	395		6,936
Whitestone REIT	1,231		10,414
Xenia Hotels & Resorts, Inc.	398		5,488
		$	497,437
Retail — 3.69%
Academy Sports & Outdoors, Inc.	447		18,854
America's Car-Mart, Inc. (a)	49		2,990
Asbury Automotive Group, Inc. (a)	59		8,915
Boot Barn Holdings, Inc. (a)	96		5,612
Buckle, Inc.	133		4,211
Caleres, Inc.	362		8,768

See accompanying notes.

85

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Retail (continued)
Cato Corp., Class A	427	$	4,074
Chico's FAS, Inc. (a)	837		4,051
Children's Place, Inc. (a)	96		2,965
Chuy's Holdings, Inc. (a)	148		3,431
Dave & Buster's Entertainment, Inc. (a)	307		9,526
Designer Brands, Inc., Class A	289		4,425
El Pollo Loco Holdings, Inc. (a)	456		4,067
Genesco, Inc. (a)	174		6,842
GMS, Inc. (a)	288		11,523
Group 1 Automotive, Inc.	46		6,572
Guess?, Inc.	222		3,257
Haverty Furniture Cos., Inc.	294		7,321
Hibbett, Inc.	69		3,437
La-Z-Boy, Inc.	186		4,198
MarineMax, Inc. (a)	126		3,753
Movado Group, Inc.	131		3,692
Patrick Industries, Inc.	95		4,165
PC Connection, Inc.	284		12,805
PriceSmart, Inc.	210		12,094
Ruth's Hospitality Group, Inc.	439		7,401
Sally Beauty Holdings, Inc. (a)	798		10,055
Shoe Carnival, Inc.	148		3,173
Sonic Automotive, Inc., Class A	91		3,940
Zumiez, Inc. (a)	140		3,014
		$	189,131
Savings & Loans — 2.65%
Axos Financial, Inc. (a)	391		13,384
Banc of California, Inc.	367		5,861
Berkshire Hills Bancorp, Inc.	428		11,684
Brookline Bancorp, Inc.	829		9,658
Capitol Federal Financial, Inc.	1,307		10,848
Northfield Bancorp, Inc.	608		8,701
Northwest Bancshares, Inc.	1,479		19,981
Pacific Premier Bancorp, Inc.	611		18,917
Provident Financial Services, Inc.	888		17,316
WSFS Financial Corp.	414		19,234
		$	135,584
Semiconductors — 1.61%
Alpha & Omega Semiconductor Ltd. (a)	246		7,567
Axcelis Technologies, Inc. (a)	221		13,384
Diodes, Inc. (a)	125		8,114
FormFactor, Inc. (a)	239		5,987
Kulicke & Soffa Industries, Inc.	173		6,666
MaxLinear, Inc. (a)	209		6,817
Onto Innovation, Inc. (a)	132		8,454
Photronics, Inc. (a)	590		8,626
Rambus, Inc. (a)	326		8,287
SMART Global Holdings, Inc. (a)	241		3,825
Ultra Clean Holdings, Inc. (a)	180		4,635
		$	82,362
Software — 2.57%
Allscripts Healthcare Solutions, Inc. (a)	895		13,631
Apollo Medical Holdings, Inc. (a)	140		5,460
Computer Programs and Systems, Inc. (a)	166		4,628
CSG Systems International, Inc.	378		19,989

See accompanying notes.

86

	Schedule of Investments
	Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Software (continued)
Digi International, Inc. (a)		293	$	10,129
Donnelley Financial Solutions, Inc. (a)		238		8,799
Ebix, Inc.		327		6,203
NextGen Healthcare, Inc. (a)		641		11,346
PDF Solutions, Inc. (a)		177		4,342
Progress Software Corp.		498		21,190
Simulations Plus, Inc.		163		7,912
SPS Commerce, Inc. (a)		89		11,056
Xperi Holding Corp.		510		7,211
			$	131,896
Telecommunications — 1.68%
ADTRAN Holdings, Inc.		292		5,717
ATN International, Inc.		205		7,907
Clearfield, Inc. (a)		107		11,196
Extreme Networks, Inc. (a)		471		6,156
Gogo, Inc. (a)		346		4,193
Harmonic, Inc. (a)		1,023		13,371
InterDigital, Inc.		266		10,752
NETGEAR, Inc. (a)		190		3,808
Telephone and Data Systems, Inc.		865		12,023
Viavi Solutions, Inc. (a)		836		10,910
			$	86,033
Textiles — 0.20%
UniFirst Corp.		60		10,094
Transportation — 2.14%
ArcBest Corp.		171		12,437
Atlas Air Worldwide Holdings, Inc. (a)		154		14,718
Dorian LPG Ltd.		274		3,718
Forward Air Corp.		274		24,731
Heartland Express, Inc.		946		13,537
Hub Group, Inc., Class A (a)		348		24,005
Marten Transport Ltd.		503		9,638
Matson, Inc.		111		6,829
			$	109,613
Water — 0.94%
American States Water Co.		236		18,396
California Water Service Group		347		18,283
Middlesex Water Co.		149		11,503
			$	48,182
TOTAL COMMON STOCKS			$	5,103,311
INVESTMENT COMPANIES — 0.22%		Shares Held		Value
Money Market Fund — 0.22%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (b)		11,188	$	11,188
TOTAL INVESTMENT COMPANIES			$	11,188
Total Investments			$	5,114,499
Other Assets and Liabilities — 0.14%				7,417
Total Net Assets — 100.00%			$	5,121,916
(a)	Non-income producing security.
(b)	Current yield shown is as of period end.

See accompanying notes. 87

Schedule of Investments

Principal U.S. Small-Cap Adaptive Multi-Factor ETF

September 30, 2022 (unaudited)

Portfolio Summary (unaudited)
Sector	Percent
Financial	34.79	%
Industrial	18.99	%
Consumer, Non-cyclical	17.89	%
Consumer, Cyclical	8.18	%
Technology	5.66	%
Basic Materials	4.65	%
Energy	3.42	%
Communications	3.14	%
Utilities	2.92	%
Money Market Fund	0.22	%
Other Assets and Liabilities	0.14	%
TOTAL NET ASSETS	100.00	%

See accompanying notes.

88

	Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS — 99.59%	Shares Held		Value
Advertising — 0.01%
Entravision Communications Corp., Class A	7,132	$	28,314
Aerospace & Defense — 0.50%
AAR Corp. (a)	11,848		424,395
Barnes Group, Inc.	9,521		274,967
Moog, Inc., Class A	5,380		378,483
		$	1,077,845
Agriculture — 0.29%
Alico, Inc.	1,320		37,277
Andersons, Inc.	5,329		165,359
Turning Point Brands, Inc.	3,716		78,891
Universal Corp.	4,279		197,005
Vector Group Ltd.	16,182		142,563
		$	621,095
Apparel — 1.22%
Carter's, Inc.	10,917		715,391
Crocs, Inc. (a)	6,597		452,950
Kontoor Brands, Inc.	7,032		236,346
Levi Strauss & Co., Class A	29,217		422,770
Oxford Industries, Inc.	3,350		300,763
Steven Madden Ltd.	12,918		344,523
Wolverine World Wide, Inc.	11,254		173,199
		$	2,645,942
Auto Manufacturers — 0.05%
REV Group, Inc.	9,486		104,631
Auto Parts & Equipment — 0.87%
Allison Transmission Holdings, Inc.	34,977		1,180,823
Dana, Inc.	19,788		226,177
Holley, Inc. (a)	3,718		15,058
Methode Electronics, Inc.	8,094		300,692
Standard Motor Products, Inc.	2,581		83,882
Titan International, Inc. (a)	7,018		85,199
		$	1,891,831
Banks — 8.77%
1st Source Corp.	2,667		123,482
Ameris Bancorp	10,318		461,318
Associated Banc-Corp.	10,917		219,213
BancFirst Corp.	8,703		778,657
Bancorp, Inc. (a)	11,023		242,286
BayCom Corp.	3,954		69,511
Byline Bancorp, Inc.	7,253		146,873
Cadence Bank	19,059		484,289
Camden National Corp.	3,253		138,578
Cathay General Bancorp	16,820		646,897
Central Pacific Financial Corp.	10,559		218,466
City Holding Co.	4,296		381,012
Coastal Financial Corp. (a)	2,523		100,264
Community Trust Bancorp, Inc.	3,823		155,023
ConnectOne Bancorp, Inc.	9,278		213,951
CrossFirst Bankshares, Inc. (a)	7,224		94,273
Customers Bancorp, Inc. (a)	13,964		411,659
CVB Financial Corp.	62,373		1,579,284
Dime Community Bancshares, Inc.	8,439		247,094

See accompanying notes.

89

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Banks (continued)
Eagle Bancorp, Inc.	8,329	$	373,306
Enterprise Financial Services Corp.	7,244		319,026
Equity Bancshares, Inc., Class A	2,494		73,897
Farmers National Banc Corp.	5,954		77,938
FB Financial Corp.	6,554		250,428
First BanCorp	70,734		967,641
First Bancshares, Inc.	4,436		132,503
First Busey Corp.	9,391		206,414
First Commonwealth Financial Corp.	34,282		440,181
First Financial Bancorp	17,762		374,423
First Foundation, Inc.	15,521		281,551
First Merchants Corp.	13,646		527,827
German American Bancorp, Inc.	2,876		102,702
Great Southern Bancorp, Inc.	3,380		192,897
Hancock Whitney Corp.	22,131		1,013,821
Hanmi Financial Corp.	7,859		186,101
Hope Bancorp, Inc.	37,803		477,830
Horizon Bancorp, Inc.	6,820		122,487
Independent Bank Corp.	6,595		125,965
Kearny Financial Corp.	25,778		273,762
Lakeland Bancorp, Inc.	15,529		248,619
Lakeland Financial Corp.	11,272		820,714
Mercantile Bank Corp.	3,112		92,458
Merchants Bancorp	3,012		69,487
Metropolitan Bank Holding Corp. (a)	4,067		261,752
Midland States Bancorp, Inc.	5,019		118,298
OFG Bancorp	11,609		291,734
Origin Bancorp, Inc.	3,367		129,529
Pathward Financial, Inc.	11,144		367,306
PCB Bancorp	2,767		50,000
Preferred Bank	4,201		274,031
Premier Financial Corp.	8,664		222,665
QCR Holdings, Inc.	3,528		179,716
S&T Bancorp, Inc.	8,008		234,715
Sandy Spring Bancorp, Inc.	8,574		302,319
ServisFirst Bancshares, Inc.	10,201		816,080
SouthState Corp.	5,949		470,685
Stock Yards Bancorp, Inc.	3,392		230,690
TriCo Bancshares	4,532		202,354
Veritex Holdings, Inc.	16,574		440,703
		$	19,056,685
Beverages — 0.20%
Coca-Cola Consolidated, Inc.	547		225,216
MGP Ingredients, Inc.	1,950		207,012
		$	432,228
Biotechnology — 4.79%
ACADIA Pharmaceuticals, Inc. (a)	29,667		485,352
Adicet Bio, Inc. (a)	3,019		42,930
ADMA Biologics, Inc. (a)	34,274		83,286
Agenus, Inc. (a)	76,892		157,629
Albireo Pharma, Inc. (a)	5,315		102,898
AnaptysBio, Inc. (a)	5,563		141,912
ANI Pharmaceuticals, Inc. (a)	4,397		141,320
Arcus Biosciences, Inc. (a)	13,162		344,318
BioCryst Pharmaceuticals, Inc. (a)	56,743		714,962
Cara Therapeutics, Inc. (a)	10,272		96,146

See accompanying notes.

90

	Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Biotechnology (continued)
Chinook Therapeutics, Inc. (a)	7,019	$	137,994
Cytek Biosciences, Inc. (a)	29,391		432,635
Cytokinetics, Inc. (a)	20,449		990,754
Dynavax Technologies Corp. (a)	41,353		431,725
Evolus, Inc. (a)	6,554		52,760
EyePoint Pharmaceuticals, Inc. (a)	3,549		28,073
Innoviva, Inc. (a)	28,033		325,463
Intercept Pharmaceuticals, Inc. (a)	12,812		178,727
Intra-Cellular Therapies, Inc. (a)	21,774		1,013,144
Ionis Pharmaceuticals, Inc. (a)	27,425		1,213,008
iTeos Therapeutics, Inc. (a)	14,045		267,557
KemPharm, Inc. (a),(b)	11,610		72,446
Ligand Pharmaceuticals, Inc. (a)	3,592		309,307
Lineage Cell Therapeutics, Inc. (a),(b)	14,937		16,879
Maravai LifeSciences Holdings, Inc., Class A (a)	41,485		1,059,112
Myriad Genetics, Inc. (a)	12,810		244,415
Organogenesis Holdings, Inc. (a)	16,671		54,014
Prothena Corp. PLC (a)	8,454		512,566
REGENXBIO, Inc. (a)	7,254		191,723
Selecta Biosciences, Inc. (a)	26,843		44,023
TransMedics Group, Inc. (a)	1,707		71,250
Travere Therapeutics, Inc. (a)	16,803		414,026
Viridian Therapeutics, Inc. (a)	1,802		36,959
		$	10,409,313
Chemicals — 1.88%
AdvanSix, Inc.	5,031		161,495
American Vanguard Corp.	5,367		100,363
Balchem Corp.	6,498		790,027
Cabot Corp.	13,830		883,598
Ingevity Corp. (a)	7,451		451,754
Intrepid Potash, Inc. (a)	3,118		123,379
Minerals Technologies, Inc.	5,046		249,323
NewMarket Corp.	1,225		368,517
Sensient Technologies Corp.	10,761		746,168
Trinseo PLC	11,037		202,198
		$	4,076,822
Coal — 1.83%
Alpha Metallurgical Resources, Inc.	3,820		522,729
Arch Resources, Inc.	9,969		1,182,323
CONSOL Energy, Inc.	5,615		361,157
Peabody Energy Corp. (a)	54,576		1,354,576
Ramaco Resources, Inc.	6,438		59,230
SunCoke Energy, Inc.	17,507		101,716
Warrior Met Coal, Inc.	13,528		384,736
		$	3,966,467
Commercial Services — 5.68%
AMN Healthcare Services, Inc. (a)	1,709		181,086
Brink's Co.	17,654		855,160
Carriage Services, Inc.	3,499		112,528
Cass Information Systems, Inc.	3,370		116,905
CBIZ, Inc. (a)	9,029		386,261
CorVel Corp. (a)	1,599		221,350
CRA International, Inc.	1,125		99,832
Cross Country Healthcare, Inc. (a)	8,424		238,989
Deluxe Corp.	7,723		128,588

See accompanying notes.

91

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Commercial Services (continued)
DLH Holdings Corp. (a)	998	$	12,245
Driven Brands Holdings, Inc. (a)	9,643		269,811
EVERTEC, Inc.	12,915		404,885
Forrester Research, Inc. (a)	1,945		70,039
Franklin Covey Co. (a)	1,376		62,457
Graham Holdings Co., Class B	637		342,693
Grand Canyon Education, Inc. (a)	8,616		708,666
H&R Block, Inc.	60,115		2,557,292
Hackett Group, Inc.	3,957		70,118
Herc Holdings, Inc.	5,150		534,982
ICF International, Inc.	3,379		368,379
Information Services Group, Inc.	6,674		31,768
Insperity, Inc.	5,903		602,637
John Wiley & Sons, Inc., Class A	5,679		213,303
Kforce, Inc.	3,067		179,880
Korn Ferry	13,008		610,726
Laureate Education, Inc., Class A	38,321		404,287
Medifast, Inc.	2,403		260,389
Monro, Inc.	7,196		312,738
Multiplan Corp. (a)	44,460		127,156
Progyny, Inc. (a)	12,842		475,925
Resources Connection, Inc.	7,029		127,014
Strategic Education, Inc.	2,289		140,567
Stride, Inc. (a)	5,841		245,497
Transcat, Inc. (a)	1,112		84,167
Triton International Ltd.	14,094		771,365
Universal Technical Institute, Inc. (a)	2,739		14,900
		$	12,344,585
Computers — 2.23%
Everspin Technologies, Inc. (a)	3,831		22,181
ExlService Holdings, Inc. (a)	6,439		948,851
Insight Enterprises, Inc. (a)	11,504		948,045
NetScout Systems, Inc. (a)	16,664		521,916
Rimini Street, Inc. (a)	8,897		41,460
Science Applications International Corp.	16,347		1,445,565
Super Micro Computer, Inc. (a)	6,800		374,476
Teradata Corp. (a)	17,243		535,568
		$	4,838,062
Construction Materials — 0.35%
Apogee Enterprises, Inc.	6,711		256,495
Boise Cascade Co.	8,620		512,545
		$	769,040
Distribution/Wholesale — 0.91%
A-Mark Precious Metals, Inc.	3,120		88,577
Core & Main, Inc., Class A (a)	28,290		643,315
G-III Apparel Group Ltd. (a)	6,209		92,824
Hudson Technologies, Inc. (a)	4,329		31,818
ScanSource, Inc. (a)	4,247		112,163
Titan Machinery, Inc. (a)	3,955		111,768
Univar Solutions, Inc. (a)	32,700		743,598
Veritiv Corp. (a)	1,545		151,055
		$	1,975,118
Diversified Financial Services — 3.70%
Amerant Bancorp, Inc.	7,255		180,214

See accompanying notes.

92

Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Diversified Financial Services (continued)
Bread Financial Holdings, Inc.	27,325	$	859,371
Cohen & Steers, Inc.	5,476		342,962
Columbia Financial, Inc. (a)	8,421		177,936
Consumer Portfolio Services, Inc. (a)	3,025		21,992
Diamond Hill Investment Group, Inc.	406		66,990
Encore Capital Group, Inc. (a)	24,470		1,112,896
International Money Express, Inc. (a)	7,343		167,347
Moelis & Co., Class A	25,080		847,955
Mr Cooper Group, Inc. (a)	30,399		1,231,159
Piper Sandler Cos.	5,149		539,306
PRA Group, Inc. (a)	16,850		553,691
Regional Management Corp.	1,944		54,510
StepStone Group, Inc., Class A	10,783		264,291
Victory Capital Holdings, Inc., Class A	10,539		245,664
Virtu Financial, Inc., Class A	49,742		1,033,141
Virtus Investment Partners, Inc.	2,078		331,483
		$	8,030,908
Electric — 1.28%
Avista Corp.	25,738		953,593
Otter Tail Corp.	6,785		417,413
Portland General Electric Co.	32,270		1,402,454
		$	2,773,460
Electrical Components & Equipment — 0.89%
Belden, Inc.	9,856		591,557
Encore Wire Corp.	6,119		706,990
Energizer Holdings, Inc.	21,409		538,222
Insteel Industries, Inc.	3,651		96,861
		$	1,933,630
Electronics — 2.09%
Advanced Energy Industries, Inc.	5,046		390,611
Avnet, Inc.	24,843		897,329
Badger Meter, Inc.	4,066		375,658
Benchmark Electronics, Inc.	7,360		182,381
Comtech Telecommunications Corp.	4,782		47,868
CTS Corp.	4,386		182,677
CyberOptics Corp. (a)	900		48,402
Knowles Corp. (a)	46,438		565,150
Napco Security Technologies, Inc. (a)	4,677		136,007
NVE Corp.	1,004		46,837
Sanmina Corp. (a)	16,455		758,246
Standard BioTools, Inc. (a)	15,161		16,677
TTM Technologies, Inc. (a)	23,545		310,323
Vishay Intertechnology, Inc.	32,311		574,813
		$	4,532,979
Engineering & Construction — 0.85%
Arcosa, Inc.	5,821		332,845
Comfort Systems USA, Inc.	6,130		596,633
Granite Construction, Inc.	12,943		328,623
MYR Group, Inc. (a)	3,136		265,713
NV5 Global, Inc. (a)	1,707		211,360
Sterling Infrastructure, Inc. (a)	5,342		114,693
		$	1,849,867

See accompanying notes.

93

	Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Entertainment — 0.68%
Accel Entertainment, Inc. (a)	5,376	$	41,986
Golden Entertainment, Inc. (a)	4,913		171,415
Monarch Casino & Resort, Inc. (a)	1,737		97,515
RCI Hospitality Holdings, Inc.	1,343		87,752
Red Rock Resorts, Inc., Class A	10,655		365,040
SeaWorld Entertainment, Inc. (a)	15,878		722,608
		$	1,486,316
Environmental Control — 0.44%
Casella Waste Systems, Inc., Class A (a)	12,454		951,361
Food — 1.79%
Hostess Brands, Inc. (a)	74,062		1,721,201
Ingles Markets, Inc., Class A	2,426		192,163
Natural Grocers by Vitamin Cottage, Inc.	1,243		13,412
Seaboard Corp.	46		156,522
Simply Good Foods Co. (a)	11,635		372,204
SpartanNash Co.	6,016		174,584
Sprouts Farmers Market, Inc. (a)	33,322		924,686
United Natural Foods, Inc. (a)	9,613		330,399
		$	3,885,171
Food Service — 0.19%
Healthcare Services Group, Inc.	34,512		417,250
Gas — 1.24%
Chesapeake Utilities Corp.	2,836		327,246
ONE Gas, Inc.	13,747		967,652
Southwest Gas Holdings, Inc.	5,731		399,737
Spire, Inc.	16,103		1,003,700
		$	2,698,335
Hand/Machine Tools — 0.27%
Franklin Electric Co., Inc.	7,116		581,448
Healthcare — Products — 4.56%
Accuray, Inc. (a)	20,120		41,850
AngioDynamics, Inc. (a)	8,311		170,043
Artivion, Inc. (a)	4,612		63,830
Atrion Corp.	170		96,050
Avanos Medical, Inc. (a)	10,921		237,859
Axogen, Inc. (a)	6,215		74,083
Axonics, Inc. (a)	7,391		520,622
Bioventus, Inc., Class A (a)	3,372		23,604
Cardiovascular Systems, Inc. (a)	7,614		105,530
Castle Biosciences, Inc. (a)	3,248		84,708
CONMED Corp.	9,201		737,644
Cue Health, Inc. (a),(b)	11,761		35,401
Cutera, Inc. (a)	2,533		115,505
Eargo, Inc. (a)	24,710		25,945
Glaukos Corp. (a)	9,042		481,396
Haemonetics Corp. (a)	11,623		860,451
Inari Medical, Inc. (a)	8,246		598,989
Inogen, Inc. (a)	4,296		104,307
Integer Holdings Corp. (a)	7,552		469,961
iRadimed Corp.	1,536		46,172
iRhythm Technologies, Inc. (a)	4,299		538,579
Lantheus Holdings, Inc. (a)	8,373		588,873
LeMaitre Vascular, Inc.	3,262		165,318

See accompanying notes.

94

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Healthcare — Products (continued)
Meridian Bioscience, Inc. (a)	13,515	$	426,128
Merit Medical Systems, Inc. (a)	9,488		536,167
NuVasive, Inc. (a)	15,036		658,727
Orthofix Medical, Inc. (a)	3,530		67,458
Patterson Cos., Inc.	24,691		593,078
Shockwave Medical, Inc. (a)	1,608		447,137
SI-BONE, Inc. (a)	5,398		94,249
Sientra, Inc. (a),(b)	11,068		7,084
Silk Road Medical, Inc. (a)	4,792		215,640
Tactile Systems Technology, Inc. (a)	3,713		28,924
Treace Medical Concepts, Inc. (a)	4,163		91,877
Utah Medical Products, Inc.	520		44,361
Varex Imaging Corp. (a)	18,460		390,244
ViewRay, Inc. (a)	34,168		124,372
		$	9,912,166
Healthcare — Services — 1.61%
Acadia Healthcare Co., Inc. (a)	15,152		1,184,583
Agiliti, Inc. (a)	4,042		57,841
Aveanna Healthcare Holdings, Inc. (a)	9,458		14,187
Brookdale Senior Living, Inc. (a)	57,050		243,604
Ensign Group, Inc.	8,608		684,336
LHC Group, Inc. (a)	1,246		203,920
National HealthCare Corp.	1,596		101,091
OPKO Health, Inc. (a)	83,005		156,880
Pediatrix Medical Group, Inc. (a)	15,967		263,615
Pennant Group, Inc. (a)	2,524		26,275
RadNet, Inc. (a)	7,135		145,197
Surgery Partners, Inc. (a)	7,482		175,079
U.S. Physical Therapy, Inc.	3,257		247,597
		$	3,504,205
Home Builders — 1.18%
Cavco Industries, Inc. (a)	1,131		232,715
Century Communities, Inc.	8,449		361,448
LCI Industries	3,377		342,630
Skyline Champion Corp. (a)	8,556		452,356
Tri Pointe Homes, Inc. (a)	29,682		448,495
Winnebago Industries, Inc.	13,512		718,973
		$	2,556,617
Home Furnishings — 0.09%
Arhaus, Inc. (a),(b)	3,513		24,767
Ethan Allen Interiors, Inc.	7,726		163,327
		$	188,094
Household Products — 0.29%
Edgewell Personal Care Co.	11,975		447,865
Inter Parfums, Inc.	2,521		190,235
		$	638,100
Household Products/Wares — 0.28%
ACCO Brands Corp.	14,941		73,211
Quanex Building Products Corp.	6,208		112,737
Spectrum Brands Holdings, Inc.	11,044		431,048
		$	616,996

See accompanying notes.

95

Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Insurance — 3.30%
American Equity Investment Life Holding Co.	24,110	$	899,062
Essent Group Ltd.	11,539		402,365
Jackson Financial, Inc., Class A	28,693		796,231
Kinsale Capital Group, Inc.	4,197		1,071,997
Radian Group, Inc.	81,844		1,578,771
RLI Corp.	9,016		923,058
Selective Insurance Group, Inc.	13,498		1,098,737
Stewart Information Services Corp.	9,400		410,216
		$	7,180,437
Internet — 0.71%
Cargurus, Inc. (a)	11,492		162,841
ChannelAdvisor Corp. (a)	5,961		135,076
ePlus, Inc. (a)	3,257		135,296
HealthStream, Inc. (a)	3,245		68,989
Perficient, Inc. (a)	6,334		411,837
Revolve Group, Inc. (a)	12,562		272,470
Shutterstock, Inc.	7,245		363,482
		$	1,549,991
Investment Companies — 0.57%
Golub Capital BDC, Inc.	99,291		1,230,215
Iron & Steel — 0.57%
Commercial Metals Co.	35,032		1,242,935
Leisure Time — 0.52%
Acushnet Holdings Corp.	7,007		304,734
Camping World Holdings, Inc., Class A	29,686		751,650
OneWater Marine, Inc., Class A (a)	2,293		69,042
		$	1,125,426
Lodging — 0.01%
Bluegreen Vacations Holding Corp.	1,004		16,586
Machinery — Construction & Mining — 0.85%
BWX Technologies, Inc.	25,439		1,281,363
Terex Corp.	19,387		576,569
		$	1,857,932
Machinery — Diversified — 1.07%
Albany International Corp., Class A	7,273		573,331
Applied Industrial Technologies, Inc.	6,080		624,902
Cactus, Inc., Class A	6,906		265,398
Kadant, Inc.	1,489		248,380
Mueller Water Products, Inc., Class A	46,967		482,351
Tennant Co.	2,413		136,479
		$	2,330,841
Media — 0.79%
AMC Networks, Inc., Class A (a)	6,167		125,190
EW Scripps Co., Class A (a)	4,777		53,837
Gray Television, Inc.	10,670		152,794
Scholastic Corp.	3,356		103,231
Sinclair Broadcast Group, Inc., Class A	13,378		242,008
World Wrestling Entertainment, Inc., Class A	14,926		1,047,357
		$	1,724,417

See accompanying notes.

96

	Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Metal Fabrication & Hardware — 0.74%
AZZ, Inc.	5,946	$	217,088
Helios Technologies, Inc.	3,027		153,166
Mueller Industries, Inc.	12,839		763,150
Ryerson Holding Corp.	3,598		92,613
Standex International Corp.	2,539		207,309
TimkenSteel Corp. (a)	12,339		184,962
		$	1,618,288
Miscellaneous Manufacturers — 0.63%
EnPro Industries, Inc.	4,073		346,124
Hillenbrand, Inc.	13,796		506,589
Myers Industries, Inc.	3,591		59,144
Sight Sciences, Inc. (a)	6,561		41,662
Smith & Wesson Brands, Inc.	18,699		193,909
Sturm Ruger & Co., Inc.	4,404		223,679
		$	1,371,107
Office & Business Equipment — 0.44%
Xerox Holdings Corp.	72,272		945,318
Office Furnishings — 0.07%
HNI Corp.	4,505		119,427
Interface, Inc.	3,835		34,477
		$	153,904
Oil & Gas — 3.13%
Brigham Minerals, Inc., Class A	9,731		240,064
California Resources Corp.	17,304		664,993
Callon Petroleum Co. (a)	25,189		881,867
Chord Energy Corp.	6,544		895,023
Civitas Resources, Inc.	15,651		898,211
Comstock Resources, Inc. (a)	33,811		584,592
Gulfport Energy Corp. (a)	1,602		141,440
Magnolia Oil & Gas Corp., Class A	34,164		676,789
Ranger Oil Corp., Class A	5,026		158,068
SandRidge Energy, Inc. (a)	10,441		170,293
SilverBow Resources, Inc. (a)	1,824		49,029
Sitio Royalties Corp. (b)	4,195		92,751
SM Energy Co.	34,835		1,310,144
VAALCO Energy, Inc.	9,966		43,452
		$	6,806,716
Oil & Gas Services — 0.47%
Archrock, Inc.	23,195		148,912
ChampionX Corp.	34,022		665,811
Solaris Oilfield Infrastructure, Inc., Class A	3,728		34,894
Weatherford International PLC (a)	5,246		169,393
		$	1,019,010
Packaging & Containers — 0.24%
Greif, Inc., Class A	6,089		362,721
Matthews International Corp., Class A	3,597		80,609
UFP Technologies, Inc. (a)	901		77,342
		$	520,672
Pharmaceuticals — 4.42%
Aerie Pharmaceuticals, Inc. (a)	10,574		159,985
Agios Pharmaceuticals, Inc. (a)	12,338		348,919

See accompanying notes.

97

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Pharmaceuticals (continued)
Akebia Therapeutics, Inc. (a)	143,795	$	45,468
Alkermes PLC (a)	31,798		710,049
Amneal Pharmaceuticals, Inc. (a)	21,656		43,745
Amphastar Pharmaceuticals, Inc. (a)	7,387		207,575
Anika Therapeutics, Inc. (a)	2,891		68,806
Catalyst Pharmaceuticals, Inc. (a)	21,165		271,547
Clovis Oncology, Inc. (a),(b)	87,188		103,754
Coherus Biosciences, Inc. (a)	21,073		202,512
Collegium Pharmaceutical, Inc. (a)	8,266		132,421
Corcept Therapeutics, Inc. (a)	21,655		555,234
Eagle Pharmaceuticals, Inc. (a)	3,947		104,280
Enanta Pharmaceuticals, Inc. (a)	5,010		259,869
Harmony Biosciences Holdings, Inc. (a)	8,158		361,318
Ironwood Pharmaceuticals, Inc. (a)	96,826		1,003,117
Jounce Therapeutics, Inc. (a)	8,209		19,209
Merus NV (a)	3,143		62,954
Option Care Health, Inc. (a)	22,369		703,952
Owens & Minor, Inc.	19,454		468,841
Pacira BioSciences, Inc. (a)	22,106		1,175,818
Paratek Pharmaceuticals, Inc. (a),(b)	9,814		25,222
PetIQ, Inc. (a)	6,269		43,256
Phibro Animal Health Corp., Class A	3,663		48,681
Premier, Inc., Class A	32,238		1,094,158
Prestige Consumer Healthcare, Inc. (a)	11,903		593,126
Supernus Pharmaceuticals, Inc. (a)	13,525		457,821
USANA Health Sciences, Inc. (a)	1,950		109,298
Vanda Pharmaceuticals, Inc. (a)	13,641		134,773
Xeris Biopharma Holdings, Inc. (a)	51,141		79,780
		$	9,595,488
Pipelines — 0.89%
Antero Midstream Corp.	99,425		912,721
Equitrans Midstream Corp.	112,081		838,366
Kinetik Holdings, Inc. (b)	5,810		189,290
		$	1,940,377
Real Estate — 0.61%
Alexander & Baldwin, Inc.	11,728		194,450
Douglas Elliman, Inc.	9,398		38,532
Kennedy-Wilson Holdings, Inc.	19,996		309,138
Marcus & Millichap, Inc.	3,139		102,896
McGrath RentCorp	3,017		253,006
Newmark Group, Inc., Class A	29,093		234,490
RMR Group, Inc., Class A	3,174		75,192
St. Joe Co.	3,956		126,711
		$	1,334,415
REITs — 6.26%
Alexander's, Inc.	782		163,407
Ares Commercial Real Estate Corp.	22,967		240,005
Brandywine Realty Trust	63,732		430,191
Broadstone Net Lease, Inc.	30,496		473,603
CareTrust REIT, Inc.	27,912		505,486
Corporate Office Properties Trust	30,392		706,006
CTO Realty Growth, Inc.	4,732		88,678
EPR Properties	19,641		704,326
Essential Properties Realty Trust, Inc.	38,631		751,373
Franklin BSP Realty Trust, Inc.	22,229		239,406

See accompanying notes.

98

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
REITs (continued)
Franklin Street Properties Corp.	20,312	$	53,421
GEO Group, Inc. (a)	54,924		422,915
Getty Realty Corp.	13,521		363,580
Highwoods Properties, Inc.	37,474		1,010,299
Industrial Logistics Properties Trust	18,826		103,543
KKR Real Estate Finance Trust, Inc.	50,056		813,410
LTC Properties, Inc.	11,443		428,540
LXP Industrial Trust	112,180		1,027,569
National Health Investors, Inc.	11,391		643,933
NexPoint Residential Trust, Inc.	3,255		150,413
One Liberty Properties, Inc.	2,421		50,889
PotlatchDeltic Corp.	13,714		562,823
Ready Capital Corp.	63,589		644,792
Retail Opportunity Investments Corp.	50,921		700,673
Saul Centers, Inc.	1,184		44,400
SITE Centers Corp.	64,729		693,248
SL Green Realty Corp.	22,774		914,604
Urban Edge Properties	41,277		550,635
Urstadt Biddle Properties, Inc., Class A	7,849		121,738
		$	13,603,906
Retail — 7.56%
Academy Sports & Outdoors, Inc.	40,400		1,704,072
Bassett Furniture Industries, Inc.	993		15,570
Beacon Roofing Supply, Inc. (a)	13,189		721,702
Bloomin' Brands, Inc.	25,221		462,301
BlueLinx Holdings, Inc. (a)	2,768		171,893
Boot Barn Holdings, Inc. (a)	8,098		473,409
Buckle, Inc.	12,100		383,086
Build-A-Bear Workshop, Inc.	3,826		51,001
Caleres, Inc.	9,960		241,231
Cato Corp., Class A	2,999		28,610
Cheesecake Factory, Inc.	14,229		416,625
Children's Place, Inc. (a)	7,264		224,385
Dave & Buster's Entertainment, Inc. (a)	12,804		397,308
Denny's Corp. (a)	9,509		89,480
Destination XL Group, Inc. (a)	6,197		33,588
Dillard's, Inc., Class A	2,899		790,731
Duluth Holdings, Inc., Class B (a)	2,198		15,474
Foot Locker, Inc.	42,786		1,331,928
Franchise Group, Inc.	5,608		136,274
Genesco, Inc. (a)	2,534		99,637
GMS, Inc. (a)	6,080		243,261
Group 1 Automotive, Inc.	3,928		561,193
Haverty Furniture Cos., Inc.	4,965		123,629
Hibbett, Inc.	6,911		344,237
Jack in the Box, Inc.	11,492		851,212
JOANN, Inc.	4,062		26,890
La-Z-Boy, Inc.	9,857		222,472
Movado Group, Inc.	2,426		68,365
MSC Industrial Direct Co., Inc., Class A	21,655		1,576,701
National Vision Holdings, Inc. (a)	14,681		479,335
Nu Skin Enterprises, Inc., Class A	11,516		384,289
Papa John's International, Inc.	11,506		805,535
Patrick Industries, Inc.	6,068		266,021
PC Connection, Inc.	1,066		48,066
PriceSmart, Inc.	2,953		170,063
Qurate Retail, Inc., Series A	82,550		165,926

See accompanying notes.

99

Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Retail (continued)
Rush Enterprises, Inc., Class A	6,303	$	276,450
Ruth's Hospitality Group, Inc.	4,882		82,311
Sally Beauty Holdings, Inc. (a)	24,002		302,425
Shoe Carnival, Inc.	4,675		100,232
Signet Jewelers Ltd.	18,660		1,067,165
Sonic Automotive, Inc., Class A	6,306		273,050
Tilly's, Inc., Class A	7,600		52,592
TravelCenters of America, Inc. (a)	2,061		111,150
Winmark Corp.	163		35,263
		$	16,426,138
Savings & Loans — 0.83%
Brookline Bancorp, Inc.	25,796		300,523
Flushing Financial Corp.	8,553		165,672
Hingham Institution For Savings	180		45,200
Northfield Bancorp, Inc.	10,559		151,099
Pacific Premier Bancorp, Inc.	17,989		556,939
Provident Financial Services, Inc.	25,895		504,953
Southern Missouri Bancorp, Inc.	1,569		80,066
		$	1,804,452
Semiconductors — 2.14%
Aehr Test Systems (a),(b)	14,565		205,366
Alpha & Omega Semiconductor Ltd. (a)	8,447		259,830
Axcelis Technologies, Inc. (a)	6,915		418,772
Diodes, Inc. (a)	7,131		462,873
EMCORE Corp. (a)	8,667		14,474
MACOM Technology Solutions Holdings, Inc. (a)	11,449		592,944
MaxLinear, Inc. (a)	10,192		332,463
Onto Innovation, Inc. (a)	5,836		373,796
Photronics, Inc. (a)	14,721		215,221
Rambus, Inc. (a)	25,773		655,150
Semtech Corp. (a)	11,044		324,804
SiTime Corp. (a)	2,907		228,868
SMART Global Holdings, Inc. (a)	23,064		366,026
Veeco Instruments, Inc. (a)	11,187		204,946
		$	4,655,533
Software — 4.87%
Allscripts Healthcare Solutions, Inc. (a)	48,514		738,868
American Software, Inc., Class A	2,858		43,785
Blackbaud, Inc. (a)	10,627		468,226
Box, Inc., Class A (a)	51,972		1,267,597
Cerence, Inc. (a)	19,469		306,637
CommVault Systems, Inc. (a)	12,684		672,759
Computer Programs and Systems, Inc. (a)	4,186		116,706
CSG Systems International, Inc.	13,376		707,323
Definitive Healthcare Corp. (a)	10,120		157,265
Digi International, Inc. (a)	5,856		202,442
Donnelley Financial Solutions, Inc. (a)	6,704		247,847
DoubleVerify Holdings, Inc. (a)	12,635		345,567
Doximity, Inc., Class A (a)	31,105		939,993
Ebix, Inc.	3,494		66,281
Evolent Health, Inc., Class A (a)	11,116		399,398
Loyalty Ventures, Inc. (a),(b)	8,079		9,776
MeridianLink, Inc. (a)	4,897		79,723
N-able, Inc. (a)	17,527		161,774
NextGen Healthcare, Inc. (a)	18,107		320,494

See accompanying notes.

100

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Software (continued)
PDF Solutions, Inc. (a)	3,218	$	78,938
Privia Health Group, Inc. (a)	10,907		371,492
Progress Software Corp.	12,328		524,556
Sciplay Corp., Class A (a)	7,384		86,836
Simulations Plus, Inc.	2,543		123,437
SPS Commerce, Inc. (a)	3,845		477,664
Tabula Rasa HealthCare, Inc. (a)	15,175		72,840
Verint Systems, Inc. (a)	27,189		913,007
Verra Mobility Corp. (a)	27,792		427,163
Xperi Holding Corp.	18,696		264,361
		$	10,592,755
Telecommunications — 2.11%
A10 Networks, Inc.	24,970		331,352
ADTRAN Holdings, Inc.	21,569		422,321
Clearfield, Inc. (a)	3,480		364,147
CommScope Holding Co., Inc. (a)	107,550		990,535
EchoStar Corp., Class A (a)	9,964		164,107
Extreme Networks, Inc. (a)	38,886		508,240
Gogo, Inc. (a)	17,490		211,979
Harmonic, Inc. (a)	27,139		354,707
InterDigital, Inc.	8,187		330,919
Telephone and Data Systems, Inc.	37,691		523,905
Viasat, Inc. (a)	12,348		373,280
		$	4,575,492
Toys, Games & Hobbies — 0.07%
Funko, Inc., Class A (a)	7,966		161,073
Transportation — 3.89%
Air Transport Services Group, Inc. (a)	12,793		308,183
ArcBest Corp.	9,145		665,116
Atlas Air Worldwide Holdings, Inc. (a)	21,419		2,047,014
Daseke, Inc. (a)	13,737		74,317
Dorian LPG Ltd.	13,742		186,479
Eagle Bulk Shipping, Inc.	5,018		216,677
Forward Air Corp.	4,538		409,600
Genco Shipping & Trading Ltd.	15,865		198,789
Hub Group, Inc., Class A (a)	7,020		484,240
International Seaways, Inc.	16,563		581,858
Marten Transport Ltd.	15,038		288,128
Matson, Inc.	10,337		635,932
PAM Transportation Services, Inc. (a)	1,189		36,811
Pangaea Logistics Solutions Ltd.	6,439		29,748
Ryder System, Inc.	19,413		1,465,487
Saia, Inc. (a)	993		188,670
Schneider National, Inc., Class B	30,855		626,357
		$	8,443,406
Trucking & Leasing — 0.28%
GATX Corp.	7,022		597,923
Water — 0.54%
American States Water Co.	9,593		747,774
Artesian Resources Corp., Class A	1,364		65,636
SJW Group	6,272		361,267
		$	1,174,677
TOTAL COMMON STOCKS		$	216,394,311

See accompanying notes.

101

				Schedule of Investments
			Principal U.S. Small-Cap Multi-Factor ETF
				September 30, 2022 (unaudited)
INVESTMENT COMPANIES — 0.60%											Shares Held		Value
Money Market Funds — 0.60%
Principal Government Money Market Fund — Institutional Class 2.80% (c),(d),(e)											578,803	$	578,803
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (e)											721,099		721,099
TOTAL INVESTMENT COMPANIES												$	1,299,902
Total Investments												$	217,694,213
Other Assets and Liabilities — (0.19)%													(411,581	)
Total Net Assets — 100.00%												$	217,282,632
(a)	Non-income producing security.
(b)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $553,799 or
	0.25% of net assets.
(c)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(d)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $578,803 or 0.27% of net assets.
(e)	Current yield shown is as of period end.
	Portfolio Summary (unaudited)
Sector						Percent
Consumer, Non-cyclical							24.11	%
Financial							23.85	%
Consumer, Cyclical							13.41	%
Industrial							13.09	%
Technology							9.68	%
Energy							6.32	%
Communications							3.62	%
Utilities							3.06	%
Basic Materials							2.45	%
Money Market Funds							0.60	%
Other Assets and Liabilities							(0.19	)%
TOTAL NET ASSETS							100.00	%
			June 30, 2022			Purchases					Sales	September 30, 2022
Affiliated Securities				Value			Cost				Proceeds		Value
Principal Government Money
Market Fund — Institutional Class
2.80		%	$	5,359,834	$	13,762,230			$	18,543,261		$	578,803
			$	5,359,834	$	13,762,230			$	18,543,261		$	578,803
										Realized Gain
							Realized				from		Change in
						Gain/(Loss) on				Capital Gain			Unrealized
				Income (a)		Investments				Distributions			Gain/(Loss)
Principal Government Money
Market Fund — Institutional Class
2.80		%	$	—		$	—			$	—	$	—
			$	—		$	—			$	—	$	—
(a)	Amount excludes earnings from securities lending collateral.

See accompanying notes. 102

	Schedule of Investments
	Principal Value ETF
	September 30, 2022 (unaudited)
COMMON STOCKS — 99.34%		Shares Held		Value
Advertising — 1.08%
Omnicom Group, Inc.		15,460	$	975,371
Aerospace & Defense — 2.69%
Northrop Grumman Corp.		2,529		1,189,439
Raytheon Technologies Corp.		15,000		1,227,900
			$	2,417,339
Agriculture — 3.70%
Altria Group, Inc.		26,155		1,056,139
Archer-Daniels-Midland Co.		13,779		1,108,520
Philip Morris International, Inc.		14,068		1,167,785
			$	3,332,444
Auto Parts & Equipment — 0.99%
BorgWarner, Inc.		28,493		894,680
Banks — 7.80%
Bank of America Corp.		50,404		1,522,201
M&T Bank Corp.		6,298		1,110,463
Northern Trust Corp.		10,835		927,043
PNC Financial Services Group, Inc.		7,267		1,085,835
Wells Fargo & Co.		35,934		1,445,266
Zions Bancorp NA		18,341		932,823
			$	7,023,631
Beverages — 3.89%
Coca-Cola Co.		27,336		1,531,363
Constellation Brands, Inc., Class A		4,602		1,056,987
Molson Coors Beverage Co., Class B		18,985		911,090
			$	3,499,440
Biotechnology — 2.68%
Amgen, Inc.		5,658		1,275,313
Corteva, Inc.		19,812		1,132,256
			$	2,407,569
Chemicals — 3.19%
CF Industries Holdings, Inc.		11,390		1,096,287
Eastman Chemical Co.		11,043		784,605
FMC Corp.		9,384		991,889
			$	2,872,781
Computers — 7.60%
Accenture PLC, Class A		5,267		1,355,199
Apple, Inc.		24,999		3,454,862
International Business Machines Corp.		9,530		1,132,259
Leidos Holdings, Inc.		10,288		899,892
			$	6,842,212
Construction Materials — 1.20%
Johnson Controls International PLC		21,974		1,081,560
Diversified Financial Services — 4.37%
American Express Co.		8,323		1,122,856
Franklin Resources, Inc.		40,957		881,394
Invesco Ltd.		59,041		808,862
Raymond James Financial, Inc.		11,310		1,117,654
			$	3,930,766

See accompanying notes.

103

Schedule of Investments
Principal Value ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Electronics — 1.34%
Honeywell International, Inc.	7,248	$	1,210,199
Food — 5.97%
Conagra Brands, Inc.	31,286		1,020,862
General Mills, Inc.	15,803		1,210,668
Hershey Co.	4,958		1,093,090
J M Smucker Co.	8,011		1,100,792
Sysco Corp.	13,400		947,514
		$	5,372,926
Household Products/Wares — 1.13%
Clorox Co.	7,936		1,018,903
Insurance — 4.41%
Arthur J Gallagher & Co.	6,877		1,177,480
Assurant, Inc.	5,673		824,117
Cincinnati Financial Corp.	8,587		769,137
Marsh & McLennan Cos., Inc.	8,003		1,194,768
		$	3,965,502
Machinery — Construction & Mining — 1.17%
Caterpillar, Inc.	6,426		1,054,378
Machinery — Diversified — 3.53%
Deere & Co.	3,729		1,245,076
Dover Corp.	8,392		978,339
Otis Worldwide Corp.	14,928		952,407
		$	3,175,822
Media — 1.02%
Fox Corp., Class A	29,860		916,105
Oil & Gas — 4.17%
Chevron Corp.	12,002		1,724,327
Hess Corp.	9,922		1,081,399
Phillips 66	11,736		947,330
		$	3,753,056
Oil & Gas Services — 1.19%
Schlumberger NV	29,704		1,066,374
Packaging & Containers — 2.72%
Amcor PLC	84,424		905,869
Packaging Corp. of America	6,971		782,774
Sealed Air Corp.	17,060		759,341
		$	2,447,984
Pharmaceuticals — 9.26%
AmerisourceBergen Corp.	7,038		952,453
Becton Dickinson and Co.	4,822		1,074,486
Cardinal Health, Inc.	19,281		1,285,657
CVS Health Corp.	14,463		1,379,337
Johnson & Johnson	13,320		2,175,955
Organon & Co.	28,703		671,650
Viatris, Inc.	93,029		792,607
		$	8,332,145
Pipelines — 1.12%
Williams Cos., Inc.	35,195		1,007,633

See accompanying notes.

104

Schedule of Investments
Principal Value ETF
September 30, 2022 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
REITs — 8.44%
Essex Property Trust, Inc.	3,839	$	929,921
Kimco Realty Corp.	51,426		946,753
Public Storage	3,581		1,048,552
Realty Income Corp.	16,120		938,184
Regency Centers Corp.	16,716		900,156
Simon Property Group, Inc.	10,764		966,069
Ventas, Inc.	20,310		815,853
VICI Properties, Inc.	35,108		1,047,974
		$	7,593,462
Retail — 5.04%
Genuine Parts Co.	7,731		1,154,393
McDonald's Corp.	6,215		1,434,049
Ross Stores, Inc.	13,556		1,142,364
Walgreens Boots Alliance, Inc.	25,698		806,917
		$	4,537,723
Semiconductors — 1.54%
Texas Instruments, Inc.	8,981		1,390,079
Shipbuilding — 1.17%
Huntington Ingalls Industries, Inc.	4,770		1,056,555
Software — 4.00%
Jack Henry & Associates, Inc.	5,611		1,022,717
Microsoft Corp.	11,058		2,575,408
		$	3,598,125
Telecommunications — 2.03%
Corning, Inc.	31,554		915,697
Juniper Networks, Inc.	34,829		909,734
		$	1,825,431
Toys, Games & Hobbies — 0.90%
Hasbro, Inc.	11,963		806,545
TOTAL COMMON STOCKS		$	89,406,740
INVESTMENT COMPANIES — 0.45%	Shares Held		Value
Money Market Fund — 0.45%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 0.80% (a)	404,114	$	404,114
TOTAL INVESTMENT COMPANIES		$	404,114
Total Investments		$	89,810,854
Other Assets and Liabilities — 0.21%			191,041
Total Net Assets — 100.00%		$	90,001,895
(a) Current yield shown is as of period end.

See accompanying notes. 105

Schedule of Investments

Principal Value ETF

September 30, 2022 (unaudited)

Portfolio Summary (unaudited)

Sector	Percent
Consumer, Non-cyclical	26.63	%
Financial	25.01	%
Industrial	13.83	%
Technology	13.15	%
Consumer, Cyclical	6.93	%
Energy	6.47	%
Communications	4.13	%
Basic Materials	3.19	%
Money Market Fund	0.45	%
Other Assets and Liabilities	0.21	%
TOTAL NET ASSETS	100.00	%

See accompanying notes.

106

Principal Exchange-Traded Funds
September 30, 2022 (unaudited)

1. Security Valuation

The Funds may invest in series of Principal Funds, Inc. and other investment funds, which may include money market funds and other registered open-end investment companies. Investments in registered open-end investment companies are valued at the respective fund's closing net asset value ("NAV") per share on the day of valuation.

The Funds value securities for which market quotations are readily available at fair value, which is determined using the last reported sale price. If no sales are reported, as is regularly the case for some securities traded over-the-counter, securities are valued using the last reported bid price or an evaluated bid price provided by a pricing service. Pricing services use modeling techniques that incorporate security characteristics such as current quotations by broker/dealers, coupon, maturity, quality, type of issue, trading characteristics, other yield and risk factors and other market conditions to determine an evaluated bid price. When reliable market quotations are not considered to be readily available, which may be the case, for example, with respect to restricted securities, certain debt securities, preferred stocks, and foreign securities, the investments are valued at their fair value as determined in good faith by the Principal Global Investors, LLC ("the Advisor") under procedures established and periodically reviewed by the Board of Trustees.

The value of foreign securities used in computing the NAV per share is generally determined as of the close of the foreign exchange where the security is principally traded. Events that occur after the close of the applicable foreign market or exchange but prior to the calculation of the Fund’s NAV are reflected in the Fund’s NAV and these securities are valued at fair value. Many factors, provided by independent pricing services, are reviewed in the course of making a good faith determination of a security’s fair value including, but not limited to, price movements in American Depository Receipts (“ADRs”), futures contracts, industry indices, general indices, and foreign currencies.

To the extent the Funds invest in foreign securities listed on foreign exchanges which trade on days on which the Funds do not determine NAV, for example, weekends and other customary national U.S. holidays, the Fund’s NAV could be significantly affected on days when shares are not able to be issued or redeemed by Authorized Participants (“APs”).

Certain securities issued by companies in emerging market countries may have more than one quoted valuation at any given point in time, sometimes referred to as a “local” price and a “premium” price. The premium price is often a negotiated price, which may not consistently represent a price at which a specific transaction can be effected. It is the policy of the Funds to value such securities at prices at which it is expected those shares may be sold, and the Advisor, or any sub-advisor, is authorized to make such determinations subject to such oversight by the Board of Trustees, as may occasionally be necessary.

2. Fair Valuation

Fair value is defined as the price that the Funds would receive upon selling a security or transferring a liability in a timely transaction to an independent buyer in the principal or most advantageous market of the security at the measurement date. In determining fair value, the Funds may use one or more of the following approaches: market, income and/or cost. A hierarchy for inputs is used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available.

Observable inputs are inputs that reflect the assumptions market participants would use in pricing the asset or liability developed based on market data obtained from sources independent of the Funds. Unobservable inputs are inputs that reflect the Fund’s own estimates about the estimates market participants would use in pricing the asset or liability developed based on the best information available in the circumstances.

The three-tier hierarchy of inputs is summarized in the three broad levels listed below.

Level 1 — Quoted prices are available in active markets for identical securities as of the reporting date. Investments which are generally included in this category include listed equities and listed derivatives.

Level 2 — Other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, credit risk, etc.). Investments which are generally included in this category include certain corporate bonds, senior floating rate interests, over-the-counter (“OTC”) derivatives, mortgage-backed securities and municipal bonds.

107

Principal Exchange-Traded Funds
September 30, 2022 (unaudited) (continued)

2. Fair Valuation (continued)

Level 3 — Significant unobservable inputs (including the Funds’ assumptions in determining the fair value of investments). Investments which are generally included in this category include certain corporate bonds and certain common stocks.

The availability of observable inputs can vary from security to security and is affected by a wide variety of factors, including, for example, the type of security, whether the security is new and not yet established in the market place, and other characteristics particular to the transaction. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Funds in determining fair value is greatest for instruments categorized in Level 3.

In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety.

Fair value is a market based measure considered from the perspective of a market participant who holds the asset rather than an entity specific measure. Therefore, even when market assumptions are not readily available, the Funds’ own assumptions are set to reflect those that market participants would use in pricing the asset or liability at the measurement date. The Funds use prices and inputs that are current as of the measurement date, to the extent available.

Investments which are included in the Level 3 category may be valued using quoted prices from brokers and dealers participating in the market for these investments. These investments are classified as Level 3 investments due to the lack of market transparency and market corroboration to support these quoted prices.

Valuation models may be used as the pricing source for other investments classified as Level 3. Valuation models rely on one or more significant unobservable inputs such as prepayment rates, probability of default, or loss severity in the event of default. Significant increases in any of those inputs in isolation would result in a significantly lower fair value measurement.

The fair values of these entities are dependent on economic, political and other considerations. The values of the underlying investee entities may be affected by significant changes in the economic conditions, changes in government policies, and other factors (e.g., natural disasters, pandemics, accidents, conflicts, etc.).

The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those instruments.

During the period there were no significant purchases, sales, or transfers into or out of Level 3.

The following is a summary of the inputs used as of September 30, 2022, in valuing the Funds' securities carried at fair value:

				Level 2 —
				Other		Level 3 —
		Level 1 —		Significant		Significant
		Quoted		Observable		Unobservable
Fund		Prices		Inputs		Inputs		Totals (Level 1,2,3)
Principal Active High Yield ETF
Bonds*	$	— $		197,447,435	$		— $	197,447,435
Senior Floating Rate Interests*		—		15,396,407			—	15,396,407
Investment Companies		9,964,114		—			—	9,964,114
Total investments in securities	$	9,964,114	$	212,843,842	$		— $	222,807,956

108

Principal Exchange-Traded Funds
September 30, 2022 (unaudited) (continued)
2. Fair Valuation (continued)
				Level 2 —
				Other		Level 3 —
		Level 1 —		Significant		Significant
		Quoted		Observable		Unobservable
Fund		Prices		Inputs		Inputs		Totals (Level 1,2,3)
Principal Healthcare Innovators ETF
Common Stocks*	$	58,178,298	$	— $			— $	58,178,298
Investment Companies		1,968,682		—			—	1,968,682
Total investments in securities	$	60,146,980	$	— $			— $	60,146,980
Principal International Adaptive Multi-Factor ETF
Common Stocks*
Basic Materials	$	693,077	$	— $			— $	693,077
Communications		670,026		—			—	670,026
Consumer, Cyclical		1,151,113		—			—	1,151,113
Consumer, Non-cyclical		2,768,832		—			—	2,768,832
Diversified		25,557		—			—	25,557
Energy		729,838		—			—	729,838
Financial		2,219,911		10,442			—	2,230,353
Industrial		1,237,628		—			—	1,237,628
Technology		580,052		—			—	580,052
Utilities		508,437		—			—	508,437
Preferred Stocks*		27,563		—			—	27,563
Investment Companies		36,406		—			—	36,406
Total investments in securities	$	10,648,440	$	10,442	$		— $	10,658,882
Principal Investment Grade Corporate Active ETF
Bonds*	$	— $		64,036,945	$		— $	64,036,945
Investment Companies		5,815,011		—			—	5,815,011
Total investments in securities	$	5,815,011	$	64,036,945	$		— $	69,851,956
Derivative Assets
Interest rate contracts
Futures	$	44,389	$	— $			— $	44,389
Derivative Liabilities
Interest rate contracts
Futures	$	(135,902	) $	— $			— $	(135,902	)
Principal Millennial Global Growth ETF
Common Stocks*	$	20,310,894	$	— $			— $	20,310,894
Investment Companies		399,977		—			—	399,977
Total investments in securities	$	20,710,871	$	— $			— $	20,710,871
Principal Quality ETF
Common Stocks*	$	31,238,649	$	— $			— $	31,238,649
Investment Companies		74,105		—			—	74,105
Total investments in securities	$	31,312,754	$	— $			— $	31,312,754
Principal Real Estate Active Opportunities ETF
Common Stocks*	$	4,752,848	$	— $			— $	4,752,848
Investment Companies		124,473		—			—	124,473
Total investments in securities	$	4,877,321	$	— $			— $	4,877,321
Principal Spectrum Preferred Securities Active ETF
Bonds*	$	— $		318,557,228	$		— $	318,557,228
Investment Companies		16,194,926		—			—	16,194,926
Total investments in securities	$	16,194,926	$	318,557,228	$		— $	334,752,154
Principal Spectrum Tax-Advantaged Dividend Active ETF
Preferred Stocks*	$	2,440,497	$	— $			— $	2,440,497
Bonds*		—		17,478,236			—	17,478,236
Investment Companies		407,069		—			—	407,069
Total investments in securities	$	2,847,566	$	17,478,236	$		— $	20,325,802

109

Principal Exchange-Traded Funds
September 30, 2022 (unaudited) (continued)
2. Fair Valuation (continued)
				Level 2 —
				Other		Level 3 —
		Level 1 —		Significant		Significant
		Quoted		Observable		Unobservable
Fund		Prices		Inputs		Inputs		Totals (Level 1,2,3)
Principal Ultra-Short Active Income ETF
Bonds*	$	— $		7,351,746	$		— $	7,351,746
Investment Companies		585,582		—			—	585,582
U.S. Government & Government Agency
Obligations		—		498,303			—	498,303
Total investments in securities	$	585,582	$	7,850,049	$		— $	8,435,631
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
Common Stocks*
Basic Materials	$	82,568	$	— $			— $	82,568
Communications		607,866		—			—	607,866
Consumer, Cyclical		477,549		—			—	477,549
Consumer, Non-cyclical		1,419,208		—			—	1,419,208
Energy		231,790		—			—	231,790
Financial		799,622		—			—	799,622
Industrial		474,039		—			—	474,039
Technology		1,024,262		8,000			—	1,032,262
Utilities		276,974		—			—	276,974
Investment Companies		15,201		—			—	15,201
Total investments in securities	$	5,409,079	$	8,000	$		— $	5,417,079
Principal U.S. Mega-Cap ETF
Common Stocks*	$	997,187,265	$	— $			— $	997,187,265
Investment Companies		2,867,394		—			—	2,867,394
Total investments in securities	$	1,000,054,659	$	— $			— $	1,000,054,659
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
Common Stocks*	$	5,103,311	$	— $			— $	5,103,311
Investment Companies		11,188		—			—	11,188
Total investments in securities	$	5,114,499	$	— $			— $	5,114,499
Principal U.S. Small-Cap Multi-Factor ETF
Common Stocks*	$	216,394,311	$	— $			— $	216,394,311
Investment Companies		1,299,902		—			—	1,299,902
Total investments in securities	$	217,694,213	$	— $			— $	217,694,213
Principal Value ETF
Common Stocks*	$	89,406,740	$	— $			— $	89,406,740
Investment Companies		404,114		—			—	404,114
Total investments in securities	$	89,810,854	$	— $			— $	89,810,854
* For additional detail regarding sector classifications, please see the Schedules of Investments.

The Funds’ Schedules of Investments for the period ended September 30, 2022 has not been audited. This report is provided for the general information of the Funds’ shareholders. For more information regarding the Funds and their holdings, please see the Funds' prospectus.

110