BlackRock

U.S.

Government

Bond

Portfolio

1

(Percentages

shown

are

based

on

Net

Assets)

Schedule

of

Investments

(unaudited)

March

31,

2021

Security

Par

(000)

Par

(000)

Value

Asset-Backed

Securities

—

2.0%

(a)

Dryden

XXVIII

Senior

Loan

Fund,

Series

2013-

28A,

Class

A1LR,

(LIBOR

USD

3

Month

+

1.20%),

1.39%,

08/15/30

(b)

..........

USD

500

$

499,644

Progress

Residential

Trust,

Series

2017-SFR1,

Class

A,

2.77%,

08/17/34

...........

99

99,970

Romark

WM-R

Ltd.,

Series

2018-1A,

Class

A1,

(LIBOR

USD

3

Month

+

1.03%),

1.25%,

04/20/31

(b)

.....................

396

395,445

Total

Asset-Backed

Securities

—

2.0%

(Cost:

$995,294)

................................

995,059

Foreign

Government

Obligations

—

3.9%

China

—

3.8%

People's

Republic

of

China:

1.99%,

04/09/25

.................

CNY

6,920

1,010,669

2.68%,

05/21/30

.................

6,350

923,378

1,934,047

Russia

—

0.1%

Russian

Federation:

7.75%,

09/16/26

.................

RUB

1,616

22,428

7.65%,

04/10/30

.................

964

13,360

8.50%,

09/17/31

.................

172

2,528

38,316

Total

Foreign

Government

Obligations

—

3.9%

(Cost:

$1,909,794)

..............................

1,972,363

Non-Agency

Mortgage-Backed

Securities

—

7.6%

Commercial

Mortgage-Backed

Securities

—

6.9%

280

Park

Avenue

Mortgage

Trust,

Series

2017-280P,

Class

A,

(LIBOR

USD

1

Month

+

0.88%),

0.99%,

09/15/34

(a)(b)

.........

USD

121

121,037

BANK

(b)

:

Series

2020-BN25,

Class

B,

3.04%,

01/15/63

....................

11

11,812

Series

2020-BN26,

Class

B,

2.91%,

03/15/63

....................

164

164,297

Benchmark

Mortgage

Trust,

Series

2020-B20,

Class

B,

2.53%,

10/15/53

...........

37

35,650

BFLD

Trust,

Series

2020-EYP,

Class

A,

(LIBOR

USD

1

Month

+

1.15%),

1.26%,

10/15/35

(a)(b)

128

129,127

BX

Commercial

Mortgage

Trust

(a)

:

Series

2019-XL,

Class

A,

(LIBOR

USD

1

Month

+

0.92%),

1.03%,

10/15/36

(b)

..

94

94,110

Series

2019-XL,

Class

D,

(LIBOR

USD

1

Month

+

1.45%),

1.56%,

10/15/36

(b)

..

282

282,153

Series

2020-FOX,

Class

B,

(LIBOR

USD

1

Month

+

1.35%),

1.46%,

11/15/32

(b)

..

134

134,256

Series

2020-VIV4,

Class

A,

2.84%,

03/09/44

160

162,327

BX

Trust

(a)

:

Series

2019-OC11,

Class

A,

3.20%,

12/09/41

....................

275

287,348

Series

2021-MFM1,

Class

C,

(LIBOR

USD

1

Month

+

1.20%),

1.31%,

01/15/34

(b)

..

30

29,964

CFK

Trust,

Series

2020-MF2,

Class

B,

2.79%,

03/15/39

(a)

.....................

140

138,367

Citigroup

Commercial

Mortgage

Trust:

Series

2016-P6,

Class

B,

4.24%,

12/10/49

(b)

50

52,231

Series

2020-420K,

Class

A,

2.46%,

11/10/42

(a)

...................

130

127,855

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

Commercial

Mortgage

Trust:

Series

2017-COR2,

Class

AM,

3.80%,

09/10/50

....................

USD

19

$

21,122

Series

2017-PANW,

Class

A,

3.24%,

10/10/29

(a)

...................

350

363,806

Credit

Suisse

Mortgage

Capital

Certificates,

Series

2020-NET,

Class

A,

2.26%,

08/15/37

(a)

.....................

100

101,756

CSAIL

Commercial

Mortgage

Trust:

Series

2018-CX11,

Class

A5,

4.03%,

04/15/51

(b)

...................

42

46,639

Series

2019-C16,

Class

A3,

3.33%,

06/15/52

....................

211

225,294

Series

2019-C17,

Class

C,

3.93%,

09/15/52

80

79,370

GCT

Commercial

Mortgage

Trust,

Series

2021-GCT,

Class

A,

(LIBOR

USD

1

Month

+

0.80%),

0.91%,

02/15/38

(a)(b)

.........

100

100,019

GS

Mortgage

Securities

Corp.

Trust,

Series

2020-TWN3,

Class

A,

(LIBOR

USD

1

Month

+

2.00%),

2.11%,

11/15/37

(a)(b)

........

170

170,686

Hudson

Yards

Mortgage

Trust,

Series

2019-

30HY,

Class

D,

3.44%,

07/10/39

(a)(b)

....

101

103,197

JPMorgan

Chase

Commercial

Mortgage

Securities

Trust,

Series

2020-609M,

Class

A,

(LIBOR

USD

1

Month

+

1.37%),

1.48%,

10/15/33

(a)(b)

....................

100

100,249

KKR

Industrial

Portfolio

Trust,

Series

2020-AIP,

Class

A,

(LIBOR

USD

1

Month

+

1.04%),

1.14%,

03/15/37

(a)(b)

...............

33

32,803

Morgan

Stanley

Capital

I

Trust:

Series

2018-H3,

Class

A5,

4.18%,

07/15/51

26

29,096

Series

2018-H3,

Class

B,

4.62%,

07/15/51

(b)

34

38,128

Series

2018-SUN,

Class

A,

(LIBOR

USD

1

Month

+

0.90%),

1.01%,

07/15/35

(a)(b)

.

130

129,921

Series

2020-HR8,

Class

AS,

2.30%,

07/15/53

....................

16

15,697

Series

2020-HR8,

Class

B,

2.70%,

07/15/53

19

19,140

NYC

Commercial

Mortgage

Trust,

Series

2021-

909,

Class

A,

2.94%,

04/10/43

(a)

.......

126

129,778

3,477,235

Interest

Only

Commercial

Mortgage-Backed

Securities

—

0.7%

(b)

Benchmark

Mortgage

Trust,

Series

2020-B20,

Class

XA,

1.63%,

10/15/53

..........

1,019

110,269

CSAIL

Commercial

Mortgage

Trust,

Series

2019-C16,

Class

XA,

1.56%,

06/15/52

..

1,542

154,030

UBS

Commercial

Mortgage

Trust,

Series

2019-

C17,

Class

XA,

1.49%,

10/15/52

......

989

96,624

360,923

Total

Non-Agency

Mortgage-Backed

Securities

—

7.6%

(Cost:

$3,874,315)

..............................

3,838,158

U.S.

Government

Sponsored

Agency

Securities

—

61.5%

Agency

Obligations

—

0.9%

Federal

Home

Loan

Bank,

4.00%, 04/10/28

.

400

469,381

Collateralized

Mortgage

Obligations

—

0.4%

Federal

National

Mortgage

Association,

Series

2011-8,

Class

ZA,

4.00%, 02/25/41

.....

120

127,021

Government

National

Mortgage

Association

Variable

Rate

Notes,

Series

2014-107,

Class

WX,

6.79%, 07/20/39

(b)

.............

75

88,307

215,328

BlackRock

U.S.

Government

Bond

Portfolio

2

(Percentages

shown

are

based

on

Net

Assets)

Schedule

of

Investments

(unaudited)

(continued)

March

31,

2021

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

—

0.7%

Federal

Home

Loan

Mortgage

Corp.

Variable

Rate

Notes

(b)

:

Series

2019-SB60,

Class

A10F,

3.31%, 01/25/29

...............

USD

191

$

199,049

Series

2019-SB61,

Class

A10F,

3.17%, 01/25/29

...............

145

150,255

Government

National

Mortgage

Association,

Series

2019-7,

Class

V,

3.00%, 05/16/35

.

20

21,448

370,752

Interest

Only

Collateralized

Mortgage

Obligations

—

0.4%

Federal

National

Mortgage

Association:

Series

2020-32,

4.00%, 05/25/50

......

156

22,406

Series

2020-32,

Class

PI,

4.00%, 05/25/50

176

27,965

Government

National

Mortgage

Association:

Series

2020-115,

Class

IM,

3.50%, 08/20/50

189

23,995

Series

2020-146,

Class

DI,

2.50%, 10/20/50

180

21,733

Series

2020-162,

Class

TI,

2.50%, 10/20/50

370

49,029

Series

2020-175,

Class

DI,

2.50%, 11/20/50

99

12,986

Series

2020-185,

Class

MI,

2.50%, 12/20/50

199

27,770

185,884

Interest

Only

Commercial

Mortgage-Backed

Securities

—

1.4%

Federal

Home

Loan

Mortgage

Corp.,

Series

2015-K718,

Class

X2A,

0.10%, 02/25/48

(a)

15,816

5,634

Federal

Home

Loan

Mortgage

Corp.

Multifamily

Structured

Pass-Through

Certificates

Variable

Rate

Notes

(b)

:

Series

K094,

Class

X1,

0.88%, 06/25/29

.

183

11,726

Series

K105,

Class

X1,

1.52%, 01/25/30

.

652

75,190

Series

K107,

Class

X1,

1.59%, 01/25/30

.

161

19,556

Series

K109,

Class

X1,

1.58%, 04/25/30

.

123

14,978

Series

K113,

Class

X1,

1.39%, 06/25/30

.

200

21,877

Series

K115,

Class

X1,

1.33%, 06/25/30

.

256

26,931

Series

K116,

Class

X1,

1.43%, 07/25/30

.

100

11,104

Series

K119,

Class

X1,

0.93%, 09/25/30

.

150

11,289

Series

K120,

Class

X1,

1.04%, 10/25/30

.

916

76,281

Series

K122,

Class

X1,

0.88%, 11/25/30

.

219

15,823

Government

National

Mortgage

Association

Variable

Rate

Notes

(b)

:

Series

2002-83,

0.00%, 10/16/42

......

216

2

Series

2003-17,

0.00%, 03/16/43

......

201

2

Series

2003-109,

0.00%, 11/16/43

.....

396

16

Series

2016-22,

0.79%, 11/16/55

......

1,506

55,574

Series

2016-45,

0.91%, 02/16/58

......

797

40,983

Series

2016-92,

0.84%, 04/16/58

......

235

11,308

Series

2016-113,

(LIBOR

USD

1

Month

+

0.00%),

1.15%, 02/16/58

.........

979

67,195

Series

2016-151,

1.03%, 06/16/58

.....

712

43,526

Series

2017-30,

0.63%, 08/16/58

......

332

13,204

Series

2017-44,

0.67%, 04/17/51

......

376

15,929

Series

2017-53,

0.65%, 11/16/56

......

3,076

140,011

Series

2017-61,

0.70%, 05/16/59

......

298

15,612

Series

2017-64,

0.76%, 11/16/57

......

195

10,683

704,434

Mortgage-Backed

Securities

—

57.7%

Federal

Home

Loan

Mortgage

Corp.:

2.50%, 03/01/30

-

04/01/31

..........

126

132,179

3.00%, 09/01/27

-

12/01/46

..........

266

282,308

3.50%, 04/01/31

-

01/01/48

..........

285

310,559

4.00%, 08/01/40

-

12/01/45

..........

41

45,284

4.50%, 02/01/39

-

07/01/47

..........

154

172,385

5.00%, 11/01/41

.................

66

75,686

5.50%, 06/01/41

.................

68

79,767

8.00%, 03/01/30

-

06/01/31

..........

10

10,130

Security

Par

(000)

Par

(000)

Value

Mortgage-Backed

Securities

(continued)

Federal

National

Mortgage

Association:

3.50%, 11/01/46

.................

USD

129

$

139,328

4.00%, 01/01/41

.................

4

4,271

Government

National

Mortgage

Association:

2.00%, 04/15/51

(c)

................

868

876,409

2.50%, 04/15/51

(c)

................

886

913,759

3.00%, 02/15/45

-

09/20/50

..........

461

482,660

3.00%, 04/15/51

(c)

................

1,029

1,071,448

3.50%, 01/15/42

-

10/20/46

..........

1,398

1,498,065

3.50%, 04/15/51

(c)

................

273

287,670

4.00%, 10/20/40

-

01/15/48

..........

469

510,440

4.00%, 04/15/51

(c)

................

120

128,100

4.50%, 12/20/39

-

08/20/50

..........

603

672,212

5.00%, 07/15/39

-

07/20/44

..........

47

54,933

5.00%, 04/15/51

(c)

................

126

137,933

Uniform

Mortgage-Backed

Securities:

1.50%, 04/25/36

-

04/25/51

(c)

.........

889

871,515

2.00%, 10/01/31

-

03/01/32

..........

79

80,880

2.00%, 04/25/36

-

05/25/51

(c)

.........

4,859

4,873,639

2.50%, 04/01/30

-

12/01/50

..........

549

574,667

2.50%, 04/25/36

-

06/25/51

(c)

.........

4,987

5,113,700

3.00%, 04/01/29

-

09/01/50

..........

3,186

3,361,515

3.00%, 04/25/51

(c)

................

615

640,330

3.50%, 04/01/29

-

08/01/50

..........

1,426

1,539,700

3.50%, 04/25/51

(c)

................

728

768,712

4.00%, 09/01/33

-

06/01/50

..........

1,077

1,180,780

4.00%, 04/25/36

-

04/25/51

(c)

.........

860

921,631

4.50%, 06/01/26

-

07/01/48

..........

519

580,662

4.50%, 04/25/51

(c)

................

41

44,632

5.00%, 02/01/35

-

12/01/43

..........

148

171,487

5.00%, 04/25/51

(c)

................

4

4,431

5.50%, 11/01/21

-

09/01/39

..........

191

221,126

6.00%, 04/01/35

-

09/01/40

..........

143

169,206

6.50%, 05/01/40

.................

31

37,237

29,041,376

Total

U.S.

Government

Sponsored

Agency

Securities

—

61.5%

(Cost:

$30,885,617)

..............................

30,987,155

U.S.

Treasury

Obligations

—

47.2%

U.S.

Treasury

Bonds:

4.25%, 05/15/39

.................

160

210,206

4.50%, 08/15/39

.................

160

216,675

4.38%, 11/15/39

.................

160

213,850

3.13%, 02/15/43

.................

610

694,042

2.88%, 05/15/43

-

11/15/46

..........

1,200

1,311,928

3.63%, 08/15/43

.................

610

748,703

3.75%, 11/15/43

.................

610

762,977

3.00%, 02/15/48

.................

590

661,376

2.25%, 08/15/49

.................

727

703,003

1.63%, 11/15/50

.................

105

87,495

U.S.

Treasury

Inflation

Linked

Notes,

0.13%, 01/15/31

(d)

................

734

789,586

U.S.

Treasury

Notes:

1.13%, 07/31/21

.................

2,650

2,659,524

1.75%, 07/31/21

-

07/31/24

..........

1,995

2,027,873

1.50%, 01/31/22

-

08/15/26

..........

4,050

4,118,812

1.75%, 04/30/22

(d)

................

2,230

2,269,896

2.13%, 12/31/22

-

05/15/25

..........

2,470

2,586,001

2.00%, 02/15/25

.................

1,470

1,548,266

2.25%, 08/15/27

.................

1,180

1,250,662

2.88%, 08/15/28

.................

350

384,973

3.13%, 11/15/28

.................

350

391,412

BlackRock

U.S.

Government

Bond

Portfolio

3

(Percentages

shown

are

based

on

Net

Assets)

Schedule

of

Investments

(unaudited)

(continued)

March

31,

2021

Security

Par

(000)

Par

(000)

Value

U.S.

Treasury

Obligations

(continued)

1.63%, 08/15/29

.................

USD

125

$

125,444

Total

U.S.

Treasury

Obligations

—

47.2%

(Cost:

$23,231,306)

..............................

23,762,704

Total

Long-Term

Investments

—

122.2%

(Cost:

$60,896,326)

..............................

61,555,439

Short-Term

Securities

—

14.3%

Certificates

of

Deposit

—

2.2%

Yankee

—

2.2%

(e)

Credit

Suisse

AG,

New

York,

0.30%, 09/01/21

1,100

1,100,464

Total

Certificates

of

Deposit

—

2.2%

(Cost:

$1,100,000)

..............................

1,100,464

Shares

Shares

Money

Market

Funds

—

3.8%

BlackRock

Liquidity

Funds,

T-Fund,

Institutional

Class,

0.01%

(f)*

..................

1,909,701

1,909,701

Total

Money

Market

Funds

—

3.8%

(Cost:

$1,909,701)

..............................

1,909,701

Security

Par

(000)

Pa

r

(

000)

Value

U.S.

Government

Sponsored

Agency

Securities

—

8.3%

Federal

Home

Loan

Bank

Discount

Notes,

0.04%, 09/22/21

(g)

...............

USD

4,200

$

4,199,188

Total

U.S.

Government

Sponsored

Agency

Securities

—

8.3%

(Cost:

$4,199,289)

..............................

4,199,188

Total

Short-Term

Securities

—

14.3%

(Cost:

$7,208,990)

..............................

7,209,353

Total

Options

Purchased

—

0.7%

(Cost:

$101,511)

................................

365,613

Total

Investments

Before

Options

Written

and

TBA

Sale

Commitments

—

137.2%

(Cost:

$68,206,827

)

..............................

69,130,405

Total

Options

Written

—

(0.4)%

(Premium

Received

—

$92,805)

.....................

(246,462)

TBA

Sale

Commitments

—

(16.9)%

(c)

Mortgage-Backed

Securities

—

(16.9)%

Government

National

Mortgage

Association:

3.50%

,

 04/15/51

-

05/15/51

..........

545

(575,531)

4.00%

,

 04/15/51

.................

45

(48,037)

4.50%

,

 04/15/51

.................

141

(152,500)

Uniform

Mortgage-Backed

Securities:

2.00%

,

 04/25/36

-

05/25/51

..........

2,871

(2,875,073)

2.50%

,

 04/25/36

-

05/25/51

..........

2,106

(2,162,917)

3.00%

,

 04/25/36

-

05/25/51

..........

878

(915,461)

3.50%

,

 04/25/36

-

04/25/51

..........

242

(257,899)

4.00%

,

 04/25/36

-

04/25/51

..........

188

(200,620)

1.50%

,

 04/25/51

-

05/25/51

..........

1,335

(1,288,508)

4.50%

,

 04/25/51

.................

34

(37,012)

Total

TBA

Sale

Commitments

—

(16.9)%

(Proceeds:

$8,554,527)

...........................

(8,513,558)

Total

Investments

Net

of

Options

Written

and

TBA

Sale

Commitments

—

119.9%

(Cost:

$59,559,495

)

..............................

60,370,385

Liabilities

in

Excess

of

Other

Assets

—

(19.9)%

...........

(10,000,811)

Net

Assets

—

100.0%

..............................

$

50,369,574

(a)

Security

exempt

from

registration

pursuant

to

Rule

144A

under

the

Securities

Act

of

1933,

as

amended.

These

securities

may

be

resold

in

transactions

exempt

from

registration

to

qualified

institutional

investors.

(b)

Variable

rate

security.

Interest

rate

resets

periodically.

The

rate

shown

is

the

effective

interest

rate

as

of

period

end.

Security

description

also

includes

the

reference

rate

and

spread

if

published

and

available.

(c)

Represents

or

includes

a

TBA

transaction.

(d)

All

or

a

portion

of

the

security

has

been

pledged

as

collateral

in

connection

with

outstanding

reverse

repurchase

agreements.

(e)

Issuer

is

a

U.S.

branch

of

a

foreign

domiciled

bank.

(f)

Annualized

7-day

yield

as

of

period

end.

(g)

Rates

are

discount

rates

or

a

range

of

discount

rates

as

of

period

end.

*

*

Investments

in

issuers

considered

to

be

affiliate(s)

of

the

Fund

during

the

period

ended

March

31,

2021

for

purposes

of

Section

2(a)(3)

of

the

Investment

Company

Act

of

1940,

as

amended,

      were

as

follows:

Affiliated

Issuer

Value

at

12/31/20

Purchases

at

Cost

Proceeds

from

Sale

Net

Realized

Gain

(Loss)

Change

in

Unrealized

Appreciation

(Depreciation)

Value

at

03/31/21

Shares

Held

at

03/31/21

Income

Capital

Gain

Distributions

from

Underlying

Funds

BlackRock

Liquidity

Funds,

T-Fund,

Institutional

Class

(a)

..

$

—

$

1,909,701

$

—

$

—

$

—

$

1,909,701

1,909,701

$

64

$

—

BlackRock

U.S.

Government

Bond

Portfolio

4

Schedule

of

Investments

(unaudited)

(continued)

March

31,

2021

(a)

Represents

net

amount

purchased

(sold).

Reverse

Repurchase

Agreements

Counterparty

Interest

Rate

Trade

Date

Maturity

Date

Face

Value

Face

Value

Including

Accrued

Interest

Type

of

Non-Cash

Underlying

Collateral

Remaining

Contractual

Maturity

of

the

Agreements

Deutsche

Bank

Securities,

Inc.

..............

0.05

%

03/31/21

04/01/21  

$

788,400

$

788,401

U.S.

Treasury

Obligations

Overnight

Deutsche

Bank

Securities,

Inc.

..............

0.05

03/31/21

04/01/21  

2,285,750

2,285,753

U.S.

Treasury

Obligations

Overnight

$

3,074,150

$

3,074,154

BlackRock

U.S

Government

Bond

Portfolio

5

Schedule

of

Investments

(unaudited)

(continued)

March

31,

2021

Derivative

Financial

Instruments

Outstanding

as

of

Period

End

Futures

Contracts

Description

Number

of

Contracts

Expiration

Date

Notional

Amount

(000)

Value/

Unrealized

Appreciation

(Depreciation)

Long

Contracts

U.S.

Treasury

10

Year

Note

...................................................

2

06/21/21

$

262

$

(202)

U.S.

Treasury

Long

Bond

....................................................

8

06/21/21

1,239

4,764

U.S.

Treasury

2

Year

Note

....................................................

49

06/30/21

10,816

(4,915)

U.S.

Treasury

5

Year

Note

....................................................

32

06/30/21

3,951

(42,803)

(43,156)

Short

Contracts

U.S.

Treasury

10

Year

Ultra

Note

...............................................

20

06/21/21

2,878

51,052

U.S.

Treasury

Ultra

Bond

....................................................

3

06/21/21

546

6,237

90-day

Eurodollar

.........................................................

1

09/18/23

247

187

90-day

Eurodollar

.........................................................

30

09/16/24

7,371

25,843

83,319

$

40,163

Forward

Foreign

Currency

Exchange

Contracts

Currency

Purchased

Currency

Sold

Counterparty

Settlement

Date

Unrealized

Appreciation  

(Depreciation)

MXN

205,232

USD

10,000

BNP

Paribas

SA

04/22/21

$

22

MXN

208,108

USD

10,000

State

Street

Bank

and

Trust

Co.

04/22/21

163

RUB

765,286

USD

10,000

Morgan

Stanley

&

Co.

International

plc

04/22/21

103

USD

11,922

EUR

10,000

Banco

Santander

SA

04/22/21

191

USD

10,000

INR

731,590

Goldman

Sachs

International

04/22/21

36

USD

10,000

JPY

1,090,996

JPMorgan

Chase

Bank

NA

04/22/21

145

ZAR

150,499

USD

10,000

Standard

Chartered

Bank

04/22/21

172

RUB

183,116

USD

2,409

Citibank

NA

05/19/21

1

RUB

368,525

USD

4,814

Credit

Suisse

International

05/19/21

36

RUB

444,469

USD

5,830

HSBC

Bank

plc

05/19/21

19

RUB

551,175

USD

7,201

Morgan

Stanley

&

Co.

International

plc

05/19/21

54

USD

2,245

RUB

167,042

Bank

of

America

NA

05/19/21

47

USD

74,036

RUB

5,508,797

Citibank

NA

05/19/21

1,533

USD

18,363

RUB

1,366,958

HSBC

Bank

plc

05/19/21

372

MXN

111,781

USD

5,203

Citibank

NA

05/26/21

235

MXN

99,234

USD

4,640

HSBC

Bank

plc

05/26/21

187

USD

20,041

CAD

25,000

BNP

Paribas

SA

06/16/21

146

USD

1,025,564

CNY

6,768,209

Standard

Chartered

Bank

06/16/21

261

USD

100,997

EUR

85,660

Bank

of

America

NA

06/16/21

387

4,110

KZT

562,188

USD

1,320

Citibank

NA

04/20/21

(1)

EUR

10,000

USD

11,810

JPMorgan

Chase

Bank

NA

04/22/21

(78)

JPY

1,090,537

USD

10,000

Natwest

Markets

plc

04/22/21

(149)

USD

10,000

IDR

146,140,000

Goldman

Sachs

International

04/22/21

(9)

USD

10,000

MXN

209,315

Credit

Suisse

International

04/22/21

(222)

USD

10,000

MXN

206,785

HSBC

Bank

plc

04/22/21

(98)

USD

10,000

RUB

760,852

BNP

Paribas

SA

04/22/21

(44)

USD

10,000

ZAR

149,682

Standard

Chartered

Bank

04/22/21

(117)

USD

10,000

ZAR

148,147

UBS

AG

04/22/21

(13)

RUB

1,048,000

USD

13,896

BNP

Paribas

SA

05/19/21

(103)

RUB

292,700

USD

3,880

Credit

Suisse

International

05/19/21

(28)

RUB

274,935

USD

3,625

HSBC

Bank

plc

05/19/21

(6)

RUB

621,428

USD

8,331

Morgan

Stanley

&

Co.

International

plc

05/19/21

(152)

USD

5,431

MXN

113,013

Barclays

Bank

plc

05/26/21

(67)

USD

4,759

MXN

98,002

UBS

AG

05/26/21

(9)

BlackRock

U.S

Government

Bond

Portfolio

6

Schedule

of

Investments

(unaudited)

(continued)

March

31,

2021

Forward

Foreign

Currency

Exchange

Contracts

(continued)

Currency

Purchased

Currency

Sold

Counterparty

Settlement

Date

Unrealized

Appreciation  

(Depreciation)

EUR

80,000

USD

95,005

Citibank

NA

06/16/21

$

(1,044)

(2,140)

$

1,970

OTC

Barrier

Options

Purchased

Description

Type

of

Option

Counterparty

Expiration  

Date

Exercise

Price

Barrier

Price/Range

Notional

Amount

(000)

Value

Put

EUR

Currency

...............

One-Touch

Bank

of

America

NA

05/06/21

USD

1.16

USD

1.16

EUR

26

$

6,762

$

–

Exchange-Traded

Options

Purchased

Description

Number

of

Contracts

Expiration

Date

Exercise

Price

Notional

Amount

(000)

Value

Put

90-day

Eurodollar

June

2021

Futures

..............

61

06/11/21

USD

99.25

USD

15,250

$

124,288

90-day

Eurodollar

September

2021

Futures

..........

117

09/10/21

USD

99.38

USD

29,250

129,431

90-day

Eurodollar

September

2021

Futures

..........

183

09/10/21

USD

99.75

USD

45,750

66,338

90-day

Eurodollar

December

2021

Futures

..........

51

12/10/21

USD

99.38

USD

12,750

12,750

$

332,807

OTC

Currency

Options

Purchased

Description

Counterparty

Expiration

Date

Exercise

Price

Notional

Amount

(000)

Value

Put

EUR

Currency

...........................

Morgan

Stanley

&

Co.

International

plc

05/06/21

USD

1.18

EUR

380

$

4,698

OTC

Interest

Rate

Swaptions

Purchased

Paid

by

the

Fund

Received

by

the

Fund

Description

Rate

Frequency

Rate

Frequency

Counterparty

Expiration

Date

Exercise

Rate

Notional

Amount

(000)

Value

Put

10-Year

Interest

Rate

Swap

(a)

2.25%

Semi-Annual

3

month

LIBOR

Quarterly

Deutsche

Bank

AG

02/22/22

2.25

%

USD

1,150

$

21,346

(a)

Forward

settling

swaption.

Exchange-Traded

Options

Written

Description

Number

of

Contracts

Expiration

Date

Exercise

Price

Notional

Amount

(000)

Value

Call

U.S.

Treasury

5

Year

Note

.......................

14

04/23/21

USD

124.50

USD

1,400

$

(547)

Put

90-day

Eurodollar

June

2021

Futures

...............

61

06/11/21

USD

98.88

USD

15,250

(71,294)

90-day

Eurodollar

September

2021

Futures

...........

22

09/10/21

USD

99.50

USD

5,500

(2,888)

90-day

Eurodollar

September

2021

Futures

...........

52

09/10/21

USD

99.00

USD

13,000

(26,975)

90-day

Eurodollar

September

2021

Futures

...........

63

09/10/21

USD

98.63

USD

15,750

(71,663)

BlackRock

U.S

Government

Bond

Portfolio

7

Schedule

of

Investments

(unaudited)

(continued)

March

31,

2021

Exchange-Traded

Options

Written

(continued)

Description

Number

of

Contracts

Expiration

Date

Exercise

Price

Notional

Amount

(000)

Value

90-day

Eurodollar

September

2021

Futures

...........

65

09/10/21

USD

99.13

USD

16,250

$

(44,281)

(217,101)

$

(217,648)

OTC

Currency

Options

Written

Description

Counterparty

Expiration

Date

Exercise

Price

Notional

Amount

(000)

Value

Put

EUR

Currency

.............................

Bank

of

America

NA

05/06/21

USD

1.16

EUR

570

$

(1,496)

OTC

Interest

Rate

Swaptions

Written

Paid

by

the

Fund

Received

by

the

Fund

Description

Rate

Frequency

Rate

Frequency

Counterparty

Expiration

Date

Exercise

Rate

Notional

Amount

(000)

Value

Call

5-Year

Interest

Rate

Swap

(a)

.

1.03%

Semi-Annual

3

month

LIBOR

Quarterly

Deutsche

Bank

AG

06/02/21

1.03

%

USD

800

$

(2,753)

10-Year

Interest

Rate

Swap

(a)

1.75%

Semi-Annual

3

month

LIBOR

Quarterly

Deutsche

Bank

AG

03/02/22

1.75

USD

200

(3,510)

10-Year

Interest

Rate

Swap

(a)

1.84%

Semi-Annual

3

month

LIBOR

Quarterly

Deutsche

Bank

AG

02/16/23

1.84

USD

42

(954)

10-Year

Interest

Rate

Swap

(a)

1.93%

Semi-Annual

3

month

LIBOR

Quarterly

Bank

of

America

NA

02/23/23

1.93

USD

42

(1,077)

(8,294)

Put

5-Year

Interest

Rate

Swap

(a)

.

3

month

LIBOR

Quarterly

1.03%

Semi-Annual

Deutsche

Bank

AG

06/02/21

1.03

USD

800

(6,010)

10-Year

Interest

Rate

Swap

(a)

3

month

LIBOR

Quarterly

1.75%

Semi-Annual

Deutsche

Bank

AG

03/02/22

1.75

USD

200

(8,174)

10-Year

Interest

Rate

Swap

(a)

3

month

LIBOR

Quarterly

1.84%

Semi-Annual

Deutsche

Bank

AG

02/16/23

1.84

USD

42

(2,516)

10-Year

Interest

Rate

Swap

(a)

3

month

LIBOR

Quarterly

1.93%

Semi-Annual

Bank

of

America

NA

02/23/23

1.93

USD

42

(2,324)

(19,024)

$

(27,318)

(a)

Forward

settling

swaption.

Centrally

Cleared

Interest

Rate

Swap

s

Paid

by

the

Fund

Received

by

the

Fund

Rate

Frequency

Rate

Frequency

Termination

Date

Notional

Amount

(000)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

28

day

MXIBTIIE

Monthly

4.29%

Monthly

01/13/23

MXN

1,466

$

(876)

$

—

$

(876)

28

day

MXIBTIIE

Monthly

4.18%

Monthly

02/16/23

MXN

671

(513)

—

(513)

28

day

MXIBTIIE

Monthly

5.22%

Monthly

03/29/23

MXN

723

92

—

92

28

day

MXIBTIIE

Monthly

4.68%

Monthly

02/27/24

MXN

945

(1,001)

—

(1,001)

28

day

MXIBTIIE

Monthly

5.47%

Monthly

03/21/24

MXN

233

(5)

—

(5)

28

day

MXIBTIIE

Monthly

5.50%

Monthly

03/21/24

MXN

234

5

—

5

2.85%

Semi-Annual

3

month

LIBOR

Quarterly

12/21/28

USD

200

(20,904)

—

(20,904)

1.61%

Semi-Annual

3

month

LIBOR

Quarterly

10/01/29

USD

400

(1,667)

—

(1,667)

1.50%

Semi-Annual

3

month

LIBOR

Quarterly

03/08/51

USD

278

45,498

—

45,498

3

month

LIBOR

Quarterly

1.70%

Semi-Annual

03/08/51

USD

139

(16,313)

—

(16,313)

3

month

LIBOR

Quarterly

1.77%

Semi-Annual

03/08/51

USD

139

(14,082)

—

(14,082)

$

(9,766)

$

—

$

(9,766)

BlackRock

U.S

Government

Bond

Portfolio

8

Schedule

of

Investments

(unaudited)

(continued)

March

31,

2021

i

Centrally

Cleared

Inflation

Swap

s

Paid

by

the

Fund

Received

by

the

Fund

Reference

Frequency

Rate

Frequency

Termination

Date

Notional

Amount

(000)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

1

month

USCPI

At

Termination

2.32%

At

Termination

01/25/31

USD

240

$

(4,931)

$

—

$

(4,931)

1

month

USCPI

At

Termination

2.34%

At

Termination

01/25/31

USD

240

(4,613)

—

(4,613)

UK

Retail

Price

Index

All

Items

Monthly

At

Termination

3.33%

At

Termination

11/15/40

GBP

20

(2,265)

—

(2,265)

UK

Retail

Price

Index

All

Items

Monthly

At

Termination

3.38%

At

Termination

12/15/40

GBP

60

(5,554)

—

(5,554)

$

(17,363)

$

—

$

(17,363)

The

following

reference

rates,

and

their

values

as

of

period

end,

are

used

for

security

descriptions:

Reference

Index

Reference

Rate

1

month

USCPI

.......................................

U.S.

Consumer

Price

Index

1.70

%

28

day

MXIBTIIE

......................................

Mexico

Interbank

TIIE

28-Day

4.29

3

month

LIBOR

.......................................

London

Interbank

Offered

Rate

0.19

Glossary

of

Terms

Used

in

this

Report

Currency

Abbreviations

CAD

Canadian

Dollar

CNY

Chinese

Yuan

EUR

Euro

GBP

British

Pound

IDR

Indonesian

Rupiah

INR

Indian

Rupee

JPY

Japanese

Yen

KZT

Kazakhstani

Tenge

MXN

Mexican

Peso

RUB

New

Russian

Ruble

USD

United

States

Dollar

ZAR

South

African

Rand

Portfolio

Abbreviations

LIBOR

London

Interbank

Offered

Rate

MXIBTIIE

Mexico

Interbank

TIIE

28-Day

OTC

Over-the-counter

TBA

To-be-announced

BlackRock

U.S

Government

Bond

Portfolio

9

Schedule

of

Investments

(unaudited)

(continued)

March

31,

2021

Fair

Value

Hierarchy

as

of

Period

End

Various

inputs

are

used

in

determining

the

fair

value

of

financial

instruments.

These

inputs

to

valuation

techniques

are

categorized

into

a

fair

value

hierarchy

consisting

of

three

broad

levels

for

financial

reporting

purposes

as

follows:

•    

Level

1

—

Unadjusted

price

quotations

in

active

markets/exchanges

for

identical

assets

or

liabilities

that

the

Fund

has

the

ability

to

access;

•    

Level

2

—

Other

observable

inputs

(including,

but

not

limited

to,

quoted

prices

for

similar

assets

or

liabilities

in

markets

that

are

active,

quoted

prices

      for

identical

or

similar

assets

or

liabilities

in

markets

that

are

not

active,

inputs

other

than

quoted

prices

that

are

observable

for

the

assets

or

liabilities

      (such

as

interest

rates,

yield

curves,

volatilities,

prepayment

speeds,

loss

severities,

credit

risks

and

default

rates)

or

other

market-corroborated

      inputs);

and

•    

Level

3

—

Unobservable

inputs

based

on

the

best

information

available

in

the

circumstances,

to

the

extent

observable

inputs

are

not

available

      (including

the

BlackRock

Global

Valuation

Methodologies

Committee's

(the

"Global

Valuation

Committee's")

assumptions

used

in

determining

the

fair

value

of

financial

instruments).

The

hierarchy

gives

the

highest

priority

to

unadjusted

quoted

prices

in

active

markets

for

identical

assets

or

liabilities

(Level

1

measurements)

and

the

lowest

priority

to

unobservable

inputs

(Level

3

measurements).

Accordingly,

the

degree

of

judgment

exercised

in

determining

fair

value

is

greatest

for

instruments

categorized

in

Level

3.

The

inputs

used

to

measure

fair

value

may

fall

into

different

levels

of

the

fair

value

hierarchy.

In

such

cases,

for

disclosure

purposes,

the

fair

value

hierarchy

classification

is

determined

based

on

the

lowest

level

input

that

is

significant

to

the

fair

value

measurement

in

its

entirety.

Investments

classified

within

Level

3

have

significant

unobservable

inputs

used

by

the

Global

Valuation

Committee

in

determining

the

price

for

Fair

Valued

Investments.

Level

3

investments

include

equity

or

debt

issued

by

privately

held

companies

or

funds.

There

may

not

be

a

secondary

market,

and/or

there

are

a

limited

number

of

investors.

The

categorization

of

a

value

determined

for

financial

instruments

is

based

on

the

pricing

transparency

of

the

financial

instruments

and

is

not

necessarily

an

indication

of

the

risks

associated

with

investing

in

those

securities.

For

information

about

the

Fund’s

policy

regarding

valuation

of

financial

instruments,

refer

to

its

most

recent

financial

statements.

The

following

table

summarizes

the

Fund’s

investments

categorized

in

the

fair

value

hierarchy.

The

breakdown

of

the

Fund's

investments

into

major

categories

is

disclosed

in

the

Schedule

of

Investments

above.

Level

1

Level

2

Level

3

Total

Assets:

Investments:

Long-Term

Investments

......................................

$

—

$

61,555,439

$

—

$

61,555,439

Short-Term

Securities:

Certificates

of

Deposit

.....................................

—

1,100,464

—

1,100,464

Money

Market

Funds

......................................

1,909,701

—

—

1,909,701

U.S.

Government

Sponsored

Agency

Securities

....................

—

4,199,188

—

4,199,188

Options

Purchased:

Foreign

currency

exchange

contracts

...........................

—

11,460

—

11,460

Interest

rate

contracts

......................................

332,807

21,346

—

354,153

Liabilities:

Investments:

TBA

Sale

Commitments

....................................

—

(8,513,558)

—

(8,513,558)

$

2,242,508

$

58,374,339

$

—

$

60,616,847

Derivative

Financial

Instruments

(a)

Assets:

Foreign

currency

exchange

contracts

............................

$

—

$

4,110

$

—

$

4,110

Interest

rate

contracts

.......................................

88,083

45,595

—

133,678

Liabilities:

Foreign

currency

exchange

contracts

............................

—

(3,636)

—

(3,636)

Interest

rate

contracts

.......................................

(265,568)

(82,679)

—

(348,247)

Other

contracts

...........................................

—

(17,363)

—

(17,363)

$

(177,485)

$

(53,973)

$

—

$

(231,458)

(a)

Derivative

financial

instruments

are

swaps,

futures

contracts,

forward

foreign

currency

exchange

contracts

and

options

written.

Swaps,

futures

contracts

and

forward

foreign

currency

exchange

contracts

are

valued

at

the

unrealized

appreciation

(depreciation)

on

the

instrument

and

options

written

are

shown

at

value.

The

Fund

may

hold

assets

and/or

liabilities

in

which

the

fair

value

approximates

the

carrying

amount

or

face

value,

including

accrued

interest,

for

financial

reporting

purposes.

As

of

period

end,

reverse

repurchase

agreements

of

$3,074,154

are

categorized

as

Level

2

w

ithin

the

fair

value

hierarchy.