UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF

REGISTERED MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-00203

MASSACHUSETTS INVESTORS TRUST

(Exact name of registrant as specified in charter)

111 Huntington Avenue, Boston, Massachusetts 02199

(Address of principal executive offices) (Zip code)

Christopher R. Bohane

Massachusetts Financial Services Company

111 Huntington Avenue

Boston, Massachusetts 02199

(Name and address of agents for service)

Registrant’s telephone number, including area code: (617) 954-5000

Date of fiscal year end: December 31

Date of reporting period: June 30, 2019

ITEM 1. REPORTS TO STOCKHOLDERS.

Semiannual Report

June 30, 2019

     Massachusetts Investors Trust

Beginning on January 1, 2021, as permitted by regulations adopted by the U.S. Securities and Exchange Commission, paper copies of the fund’s annual and semiannual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports. Instead, the complete reports will be made available on the fund’s Web site (funds.mfs.com), and you will be notified by mail each time a report is posted and provided with a Web site link to access the report.

If you are already signed up to receive shareholder reports by email, you will not be affected by this change and you need not take any action. You may sign up to receive shareholder reports and other communications from the fund by email by contacting your financial intermediary (such as a broker-dealer or bank) or, if you hold your shares directly with the fund, by calling 1-800-225-2606 or by logging on to MFS Access at mfs.com.

Beginning on January 1, 2019, you may elect to receive all future reports in paper free of charge. Contact your financial intermediary to request that you continue to receive paper copies of your shareholder reports. If you invest directly with the fund, you can call 1-800-225-2606 or send an email request to orderliterature@mfs.com to let the fund know that you wish to continue receiving paper copies of your shareholder reports. Your election to receive reports in paper will apply to all funds held in your account if you invest through your financial intermediary or all funds held with the MFS fund complex if you invest directly.

MIT-SEM

MFS® Massachusetts Investors Trust

CONTENTS

Letter from the Executive Chairman	1
Portfolio composition	2
Expense table	3
Portfolio of investments	5
Statement of assets and liabilities	10
Statement of operations	12
Statements of changes in net assets	13
Financial highlights	14
Notes to financial statements	26
Proxy voting policies and information	38
Quarterly portfolio disclosure	38
Further information	38
Information about fund contracts and legal claims	38
Provision of financial reports and summary prospectuses	38
Contact information    back cover

The report is prepared for the general information of shareholders.

It is authorized for distribution to prospective investors only when preceded or accompanied by a current prospectus.

NOT FDIC INSURED • MAY LOSE VALUE • NO BANK GUARANTEE

LETTER FROM THE EXECUTIVE CHAIRMAN

Dear Shareholders:

Slowing global growth, low inflation, and increasing trade friction between the United States and China have been hallmarks of the past 12 months. After

experiencing an uptick in market volatility in late 2018, markets steadied during the first half of 2019, thanks in large measure to the adoption of a dovish policy stance on the part of global central banks, who have largely abandoned efforts to normalize interest rates and have instead focused on supporting economic growth. Trade tensions remain high as the U.S. has ratcheted up tariffs on Chinese imports and China has retaliated. A truce of sorts was reached midyear, but significant challenges continue to confront negotiators, and it is not known whether a comprehensive agreement can be reached.

With Boris Johnson replacing Theresa May as Britain’s prime

minister, uncertainty over Brexit remains high. Johnson has adopted a more combative stance than his predecessor toward the European Union, increasing concerns that there will be a “hard” Brexit.

Markets expect that the longest economic expansion in U.S. history will continue for the time being, albeit at a slower pace. Nevertheless, slower growth and low inflation have spurred the U.S. Federal Reserve to take a more accommodative policy stance, prompting investors to anticipate several interest rate cuts in the coming year. The European Central Bank has adopted a similar position. The more accommodative environment has helped fuel a continued rise in global equities and has been broadly supportive of risk assets.

Since launching the first U.S. open-end mutual fund in 1924, MFS® has been committed to a single purpose: to create value by allocating capital responsibly for clients. Through our powerful global investment platform, we combine collective expertise, thoughtful risk management, and long-term discipline to uncover what we believe are the best investment opportunities in the market.

Respectfully,

Robert J. Manning

Executive Chairman

MFS Investment Management

August 16, 2019

The opinions expressed in this letter are subject to change and may not be relied upon for investment advice. No forecasts can be guaranteed.

1

PORTFOLIO COMPOSITION

Portfolio structure

Top ten holdings
Visa, Inc., “A”	3.3%
Alphabet, Inc., “A”	3.0%
American Tower Corp., REIT	2.8%
JPMorgan Chase & Co.	2.7%
Mastercard, Inc., “A”	2.5%
Johnson & Johnson	2.5%
Danaher Corp.	2.5%
Medtronic PLC	2.5%
Thermo Fisher Scientific, Inc.	2.5%
Fidelity National Information Services, Inc.	2.2%

GICS equity sectors (g)
Information Technology	23.4%
Health Care	16.6%
Financials	12.7%
Communication Services	9.6%
Consumer Staples	9.5%
Consumer Discretionary	8.5%
Industrials	7.4%
Energy	4.5%
Materials	4.0%
Real Estate	2.8%
Utilities	0.5%

(g) The Global Industry Classification Standard (GICS®) was developed by and/or is the exclusive property of MSCI, Inc. and S&P Global Market Intelligence Inc. (“S&P Global Market Intelligence”). GICS is a service mark of MSCI and S&P Global Market Intelligence and has been licensed for use by MFS.

Cash & Cash Equivalents includes any cash, investments in money market funds, short-term securities, and other assets less liabilities. Please see the Statement of Assets and Liabilities for additional information related to the fund’s cash position and other assets and liabilities.

Percentages are based on net assets as of June 30, 2019.

The portfolio is actively managed and current holdings may be different.

2

EXPENSE TABLE

Fund expenses borne by the shareholders during the period, January 1, 2019 through June 30, 2019

As a shareholder of the fund, you incur two types of costs: (1) transaction costs, including sales charges (loads) on certain purchase or redemption payments, and (2) ongoing costs, including management fees; distribution and service (12b-1) fees; and other fund expenses. This example is intended to help you understand your ongoing costs (in dollars) of investing in the fund and to compare these costs with the ongoing costs of investing in other mutual funds.

The example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period January 1, 2019 through June 30, 2019.

Actual Expenses

The first line for each share class in the following table provides information about actual account values and actual expenses. You may use the information in this line, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number in the first line under the heading entitled “Expenses Paid During Period” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes

The second line for each share class in the following table provides information about hypothetical account values and hypothetical expenses based on the fund’s actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the fund’s actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as sales charges (loads). Therefore, the second line for each share class in the table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs would have been higher.

3

Expense Table – continued

Share Class		Annualized Expense Ratio		Beginning Account Value 1/01/19		Ending Account Value 6/30/19		Expenses Paid During Period  (p) 1/01/19-6/30/19
A	Actual		0.70%		$1,000.00		$1,208.42		$3.83
	Hypothetical (h)		0.70%		$1,000.00		$1,021.32		$3.51
B	Actual		1.46%		$1,000.00		$1,203.91		$7.98
	Hypothetical (h)		1.46%		$1,000.00		$1,017.55		$7.30
C	Actual		1.46%		$1,000.00		$1,203.79		$7.98
	Hypothetical (h)		1.46%		$1,000.00		$1,017.55		$7.30
I	Actual		0.47%		$1,000.00		$1,209.96		$2.58
	Hypothetical (h)		0.47%		$1,000.00		$1,022.46		$2.36
R1	Actual		1.47%		$1,000.00		$1,203.52		$8.03
	Hypothetical (h)		1.47%		$1,000.00		$1,017.50		$7.35
R2	Actual		0.97%		$1,000.00		$1,206.63		$5.31
	Hypothetical (h)		0.97%		$1,000.00		$1,019.98		$4.86
R3	Actual		0.72%		$1,000.00		$1,208.16		$3.94
	Hypothetical (h)		0.72%		$1,000.00		$1,021.22		$3.61
R4	Actual		0.47%		$1,000.00		$1,209.70		$2.58
	Hypothetical (h)		0.47%		$1,000.00		$1,022.46		$2.36
R6	Actual		0.39%		$1,000.00		$1,210.64		$2.14
	Hypothetical (h)		0.39%		$1,000.00		$1,022.86		$1.96
529A	Actual		0.75%		$1,000.00		$1,208.06		$4.11
	Hypothetical (h)		0.75%		$1,000.00		$1,021.08		$3.76
529B	Actual		1.50%		$1,000.00		$1,203.52		$8.20
	Hypothetical (h)		1.50%		$1,000.00		$1,017.36		$7.50
529C	Actual		1.51%		$1,000.00		$1,203.44		$8.25
	Hypothetical (h)		1.51%		$1,000.00		$1,017.31		$7.55

(h) 5% class return per year before expenses.

(p) “Expenses Paid During Period” are equal to each class’s annualized expense ratio, as shown above, multiplied by the average account value over the period, multiplied by 181/365 (to reflect the one-half year period). Expenses paid do not include any applicable sales charges (loads). If these transaction costs had been included, your costs would have been higher.

Notes to Expense Table

Each class with a Rule 12b-1 service fee is subject to a rebate of a portion of such fee. Such rebates are included in the expense ratios above. For Class A, Class B, Class 529A, and Class 529B shares, this rebate reduced the expense ratios above by 0.02%, 0.01%, 0.01%, and 0.01%, respectively. See Note 3 in the Notes to Financial Statements for additional information.

4

PORTFOLIO OF INVESTMENTS

6/30/19 (unaudited)

The Portfolio of Investments is a complete list of all securities owned by your fund. It is categorized by broad-based asset classes.

Common Stocks - 99.5%
Issuer	Shares/Par		Value ($)
Aerospace - 3.4%
Honeywell International, Inc.		668,172	$	116,656,150
United Technologies Corp.		615,310		80,113,362
			$	196,769,512
Alcoholic Beverages - 2.5%
Diageo PLC		1,476,943	$	63,471,751
Pernod Ricard S.A.		436,665		80,462,985
			$	143,934,736
Apparel Manufacturers - 2.3%
LVMH Moet Hennessy Louis Vuitton SE		180,643	$	76,884,658
NIKE, Inc., “B”		678,620		56,970,149
			$	133,854,807
Biotechnology - 0.7%
Biogen, Inc. (a)		177,507	$	41,513,562
Broadcasting - 0.7%
Walt Disney Co.		279,285	$	38,999,357
Brokerage & Asset Managers - 3.8%
Blackstone Group LP		1,701,070	$	75,561,529
NASDAQ, Inc.		912,626		87,767,243
TD Ameritrade Holding Corp.		1,126,151		56,217,458
			$	219,546,230
Business Services - 7.8%
Accenture PLC, “A”		609,293	$	112,579,068
Amdocs Ltd.		1,115,349		69,252,019
Cognizant Technology Solutions Corp., “A”		1,377,244		87,303,497
DXC Technology Co.		960,607		52,977,476
Fidelity National Information Services, Inc.		1,037,695		127,304,423
			$	449,416,483
Cable TV - 2.0%
Comcast Corp., “A”		2,785,808	$	117,783,962
Chemicals - 1.0%
PPG Industries, Inc.		488,712	$	57,037,578

5

Portfolio of Investments (unaudited) – continued

Issuer	Shares/Par		Value ($)
Common Stocks - continued
Computer Software - 4.0%
Adobe Systems, Inc. (a)		276,922	$	81,595,067
Microsoft Corp.		767,300		102,787,508
Salesforce.com, Inc. (a)		300,489		45,593,196
			$	229,975,771
Computer Software - Systems - 1.1%
Apple, Inc.		329,531	$	65,220,776
Construction - 1.4%
Sherwin-Williams Co.		179,057	$	82,060,033
Consumer Products - 2.8%
Colgate-Palmolive Co.		1,024,572	$	73,431,075
Estee Lauder Cos., Inc., “A”		195,891		35,869,601
Kimberly-Clark Corp.		372,917		49,702,378
			$	159,003,054
Containers - 1.1%
Crown Holdings, Inc. (a)		1,039,302	$	63,501,352
Electrical Equipment - 3.0%
AMETEK, Inc.		755,445	$	68,624,624
Fortive Corp.		595,133		48,515,242
TE Connectivity Ltd.		576,341		55,201,941
			$	172,341,807
Electronics - 2.5%
Analog Devices, Inc.		501,824	$	56,640,875
Texas Instruments, Inc.		742,060		85,158,806
			$	141,799,681
Energy - Independent - 1.5%
EOG Resources, Inc.		948,879	$	88,397,568
Food & Beverages - 3.1%
Danone S.A.		963,941	$	81,659,262
Mondelez International, Inc.		1,809,468		97,530,325
			$	179,189,587
General Merchandise - 1.6%
Dollar General Corp.		406,130	$	54,892,531
Dollar Tree, Inc. (a)		362,902		38,972,046
			$	93,864,577

6

Portfolio of Investments (unaudited) – continued

Issuer	Shares/Par		Value ($)
Common Stocks - continued
Insurance - 1.1%
Chubb Ltd.		447,901	$	65,971,338
Internet - 5.8%
Alphabet, Inc., “A” (a)		158,691	$	171,830,615
Alphabet, Inc., “C” (a)		63,218		68,332,968
Facebook, Inc., “A” (a)		497,559		96,028,887
			$	336,192,470
Leisure & Toys - 1.1%
Electronic Arts, Inc. (a)		609,023	$	61,669,669
Machinery & Tools - 0.3%
Flowserve Corp.		354,384	$	18,672,493
Major Banks - 6.6%
Bank of America Corp.		4,289,484	$	124,395,036
Goldman Sachs Group, Inc.		359,915		73,638,609
JPMorgan Chase & Co.		1,387,155		155,083,929
Morgan Stanley		614,180		26,907,226
			$	380,024,800
Medical & Health Technology & Services - 0.9%
McKesson Corp.		381,155	$	51,223,420
Medical Equipment - 9.5%
Abbott Laboratories		744,497	$	62,612,198
Becton, Dickinson and Co.		225,573		56,846,652
Danaher Corp.		995,448		142,269,428
Medtronic PLC		1,459,815		142,171,383
Thermo Fisher Scientific, Inc.		481,790		141,492,087
			$	545,391,748
Natural Gas - Pipeline - 1.5%
Enterprise Products Partners LP		3,022,898	$	87,271,065
Network & Telecom - 1.2%
Cisco Systems, Inc.		1,306,665	$	71,513,775
Oil Services - 1.5%
Core Laboratories N.V.		498,003	$	26,035,597
Schlumberger Ltd.		1,496,425		59,467,929
			$	85,503,526

7

Portfolio of Investments (unaudited) – continued

Issuer	Shares/Par		Value ($)
Common Stocks - continued
Other Banks & Diversified Financials - 7.0%
BB&T Corp.		1,357,531	$	66,695,498
Mastercard, Inc., “A”		550,302		145,571,388
Visa, Inc., “A”		1,099,305		190,784,383
			$	403,051,269
Pharmaceuticals - 5.5%
Elanco Animal Health, Inc. (a)		1,529,010	$	51,680,538
Eli Lilly & Co.		560,199		62,064,447
Johnson & Johnson		1,031,657		143,689,187
Zoetis, Inc.		534,644		60,676,748
			$	318,110,920
Railroad & Shipping - 1.7%
Canadian National Railway Co.		1,032,829	$	95,516,026
Restaurants - 1.7%
Starbucks Corp.		1,158,576	$	97,123,426
Specialty Chemicals - 0.5%
DuPont de Nemours, Inc.		376,245	$	28,244,712
Specialty Stores - 4.0%
Costco Wholesale Corp.		241,426	$	63,799,235
Ross Stores, Inc.		786,235		77,931,613
Tractor Supply Co.		789,874		85,938,291
			$	227,669,139
Telecommunications - Wireless - 2.8%
American Tower Corp., REIT		797,325	$	163,013,096
Utilities - Electric Power - 0.5%
American Electric Power Co., Inc.		349,141	$	30,727,899
Total Common Stocks (Identified Cost, $3,052,831,782)			$	5,741,101,224
Investment Companies (h) - 0.7%
Money Market Funds - 0.7%
MFS Institutional Money Market Portfolio, 2.42% (v) (Identified Cost, $40,719,084)		40,722,901	$	40,726,973
Other Assets, Less Liabilities - (0.2)%				(13,690,633	)
Net Assets - 100.0%			$	5,768,137,564

8

Portfolio of Investments (unaudited) – continued

(a) Non-income producing security.

(h) An affiliated issuer, which may be considered one in which the fund owns 5% or more of the outstanding voting securities, or a company which is under common control. At period end, the aggregate values of the fund’s investments in affiliated issuers and in unaffiliated issuers were $40,726,973 and $5,741,101,224, respectively.

(v) Affiliated issuer that is available only to investment companies managed by MFS. The rate quoted for the MFS Institutional Money Market Portfolio is the annualized seven-day yield of the fund at period end.

The following abbreviations are used in this report and are defined:

REIT Real Estate Investment Trust

See Notes to Financial Statements

9

Financial Statements

STATEMENT OF ASSETS AND LIABILITIES

At 6/30/19 (unaudited)

This statement represents your fund’s balance sheet, which details the assets and liabilities comprising the total value of the fund.

Assets
Investments in unaffiliated issuers, at value (identified cost, $3,052,831,782)	$5,741,101,224
Investments in affiliated issuers, at value (identified cost, $40,719,084)	40,726,973
Cash	366,518
Receivables for
Fund shares sold	4,181,100
Dividends	3,817,891
Receivable from distributor	51,912
Other assets	199,747
Total assets	$5,790,445,365
Liabilities
Payables for
Distributions	$5,665,702
Fund shares reacquired	13,954,435
Payable to affiliates
Investment adviser	207,875
Administrative services fee	6,316
Shareholder servicing costs	2,144,264
Program manager fees	104
Payable for independent Trustees’ compensation	10,695
Accrued expenses and other liabilities	318,410
Total liabilities	$22,307,801
Net assets	$5,768,137,564
Net assets consist of
Paid-in capital	$2,915,441,195
Total distributable earnings (loss)	2,852,696,369
Net assets	$5,768,137,564
Shares of beneficial interest outstanding	182,285,900

10

Statement of Assets and Liabilities (unaudited) – continued

	Net assets		Shares outstanding		Net asset value per share (a)
Class A		$3,695,034,243		115,484,573		$32.00
Class B		54,511,074		1,762,171		30.93
Class C		176,709,518		5,839,963		30.26
Class I		446,537,985		14,395,675		31.02
Class R1		5,588,022		185,866		30.06
Class R2		127,592,370		4,207,817		30.32
Class R3		294,667,867		9,302,267		31.68
Class R4		73,098,023		2,261,710		32.32
Class R6		875,364,048		28,223,292		31.02
Class 529A		15,086,530		485,037		31.10
Class 529B		425,136		14,621		29.08
Class 529C		3,522,748		122,908		28.66

(a) Maximum offering price per share was equal to the net asset value per share for all share classes, except for Classes A and 529A, for which the maximum offering prices per share were $33.95 [100 / 94.25 x $32.00] and $33.00 [100 / 94.25 x $31.10], respectively. On sales of $50,000 or more, the maximum offering prices of Class A and Class 529A shares are reduced. A contingent deferred sales charge may be imposed on redemptions of Class A, Class B, Class C, Class 529B, and Class 529C shares. Redemption price per share was equal to the net asset value per share for Classes I, R1, R2, R3, R4, R6, and 529A.

See Notes to Financial Statements

11

Financial Statements

STATEMENT OF OPERATIONS

Six months ended 6/30/19 (unaudited)

This statement describes how much your fund earned in investment income and accrued in expenses. It also describes any gains and/or losses generated by fund operations.

Net investment income (loss)
Income
Dividends	$43,995,168
Dividends from affiliated issuers	541,526
Income on securities loaned	307,619
Other	102,506
Foreign taxes withheld	(611,750	)
Total investment income	$44,335,069
Expenses
Management fee	$9,143,334
Distribution and service fees	6,238,094
Shareholder servicing costs	2,537,408
Program manager fees	4,527
Administrative services fee	301,063
Independent Trustees’ compensation	51,917
Custodian fee	87,809
Shareholder communications	211,455
Audit and tax fees	31,043
Legal fees	27,347
Miscellaneous	192,033
Total expenses	$18,826,030
Reduction of expenses by distributor	(373,806	)
Net expenses	$18,452,224
Net investment income (loss)	$25,882,845
Realized and unrealized gain (loss)
Realized gain (loss) (identified cost basis)
Unaffiliated issuers	$160,221,973
Affiliated issuers	2,983
Foreign currency	2,575
Net realized gain (loss)	$160,227,531
Change in unrealized appreciation or depreciation
Unaffiliated issuers	$856,595,265
Affiliated issuers	7,889
Net unrealized gain (loss)	$856,603,154
Net realized and unrealized gain (loss)	$1,016,830,685
Change in net assets from operations	$1,042,713,530

See Notes to Financial Statements

12

Financial Statements

STATEMENTS OF CHANGES IN NET ASSETS

These statements describe the increases and/or decreases in net assets resulting from operations, any distributions, and any shareholder transactions.

Change in net assets	Six months ended 6/30/19 (unaudited)			Year ended 12/31/18
From operations
Net investment income (loss)		$25,882,845			$63,630,569
Net realized gain (loss)		160,227,531			713,449,426
Net unrealized gain (loss)		856,603,154			(1,036,531,193	)
Change in net assets from operations		$1,042,713,530			$(259,451,198	)
Total distributions to shareholders		$(67,819,545	)		$(649,966,982	)
Change in net assets from fund share transactions		$(321,364,943	)		$(550,977,838	)
Total change in net assets		$653,529,042			$(1,460,396,018	)
Net assets
At beginning of period		5,114,608,522			6,575,004,540
At end of period		$5,768,137,564			$5,114,608,522

See Notes to Financial Statements

13

Financial Statements

FINANCIAL HIGHLIGHTS

The financial highlights table is intended to help you understand the fund’s financial performance for the semiannual period and the past 5 fiscal years. Certain information reflects financial results for a single fund share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in the fund share class (assuming reinvestment of all distributions) held for the entire period.

	Six months ended 6/30/19			Year ended
Class A				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$26.79			$32.15			$27.94			$27.26			$28.82			$27.72
Income (loss) from investment operations
Net investment income (loss) (d)		$0.14			$0.32			$0.27			$0.27	(c)		$0.24			$0.28
Net realized and unrealized gain (loss)		5.44			(1.98	)		6.28			2.12			(0.16	)		2.74
Total from investment operations		$5.58			$(1.66	)		$6.55			$2.39			$0.08			$3.02
Less distributions declared to shareholders
From net investment income		$(0.08	)		$(0.29	)		$(0.31	)		$(0.26	)		$(0.26	)		$(0.24	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.37	)		$(3.70	)		$(2.34	)		$(1.71	)		$(1.64	)		$(1.92	)
Net asset value, end of period (x)		$32.00			$26.79			$32.15			$27.94			$27.26			$28.82
Total return (%) (r)(s)(t)(x)		20.84	(n)		(5.31	)		23.56			8.77	(c)		0.28			10.99
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		0.72	(a)		0.71			0.72			0.72	(c)		0.72			0.72
Expenses after expense reductions (f)		0.70	(a)		0.69			0.70			0.71	(c)		0.70			0.71
Net investment income (loss)		0.90	(a)		0.97			0.88			0.97	(c)		0.84			0.97
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$3,695,034			$3,150,030			$3,543,029			$3,272,859			$3,273,616			$3,422,330

See Notes to Financial Statements

14

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class B				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$25.95			$31.24			$27.20			$26.58			$28.13			$27.11
Income (loss) from investment operations
Net investment income (loss) (d)		$0.02			$0.06			$0.03			$0.06	(c)		$0.02			$0.06
Net realized and unrealized gain (loss)		5.27			(1.91	)		6.09			2.06			(0.16	)		2.67
Total from investment operations		$5.29			$(1.85	)		$6.12			$2.12			$(0.14	)		$2.73
Less distributions declared to shareholders
From net investment income		$(0.02	)		$(0.03	)		$(0.05	)		$(0.05	)		$(0.03	)		$(0.03	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.31	)		$(3.44	)		$(2.08	)		$(1.50	)		$(1.41	)		$(1.71	)
Net asset value, end of period (x)		$30.93			$25.95			$31.24			$27.20			$26.58			$28.13
Total return (%) (r)(s)(t)(x)		20.39	(n)		(6.06	)		22.61			7.95	(c)		(0.48	)		10.13
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.47	(a)		1.46			1.47			1.47	(c)		1.47			1.47
Expenses after expense reductions (f)		1.46	(a)		1.46			1.47			1.47	(c)		1.46			1.47
Net investment income (loss)		0.13	(a)		0.19			0.12			0.21	(c)		0.07			0.20
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$54,511			$53,035			$71,698			$75,916			$83,970			$96,750

See Notes to Financial Statements

15

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class C				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$25.40			$30.65			$26.73			$26.15			$27.73			$26.74
Income (loss) from investment operations
Net investment income (loss) (d)		$0.02			$0.05			$0.03			$0.06	(c)		$0.02			$0.06
Net realized and unrealized gain (loss)		5.16			(1.86	)		5.99			2.03			(0.17	)		2.65
Total from investment operations		$5.18			$(1.81	)		$6.02			$2.09			$(0.15	)		$2.71
Less distributions declared to shareholders
From net investment income		$(0.03	)		$(0.03	)		$(0.07	)		$(0.06	)		$(0.05	)		$(0.04	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.32	)		$(3.44	)		$(2.10	)		$(1.51	)		$(1.43	)		$(1.72	)
Net asset value, end of period (x)		$30.26			$25.40			$30.65			$26.73			$26.15			$27.73
Total return (%) (r)(s)(t)(x)		20.38	(n)		(6.04	)		22.62			7.97	(c)		(0.54	)		10.19
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.47	(a)		1.46			1.47			1.47	(c)		1.47			1.47
Expenses after expense reductions (f)		1.46	(a)		1.46			1.47			1.47	(c)		1.46			1.47
Net investment income (loss)		0.13	(a)		0.16			0.12			0.21	(c)		0.07			0.20
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$176,710			$162,991			$307,349			$295,541			$296,096			$301,874

See Notes to Financial Statements

16

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class I				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$25.96			$31.26			$27.23			$26.59			$28.17			$27.13
Income (loss) from investment operations
Net investment income (loss) (d)		$0.17			$0.37			$0.34			$0.32	(c)		$0.30			$0.34
Net realized and unrealized gain (loss)		5.28			(1.91	)		6.10			2.09			(0.17	)		2.69
Total from investment operations		$5.45			$(1.54	)		$6.44			$2.41			$0.13			$3.03
Less distributions declared to shareholders
From net investment income		$(0.10	)		$(0.35	)		$(0.38	)		$(0.32	)		$(0.33	)		$(0.31	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.39	)		$(3.76	)		$(2.41	)		$(1.77	)		$(1.71	)		$(1.99	)
Net asset value, end of period (x)		$31.02			$25.96			$31.26			$27.23			$26.59			$28.17
Total return (%) (r)(s)(t)(x)		21.00	(n)		(5.08	)		23.79			9.08	(c)		0.46			11.27
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		0.47	(a)		0.46			0.47			0.48	(c)		0.47			0.47
Expenses after expense reductions (f)		N/A			N/A			N/A			0.48	(c)		0.47			0.47
Net investment income (loss)		1.13	(a)		1.15			1.14			1.21	(c)		1.07			1.21
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$446,538			$377,000			$1,271,676			$1,525,636			$2,804,058			$2,822,535

See Notes to Financial Statements

17

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class R1				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$25.24			$30.47			$26.59			$26.01			$27.58			$26.61
Income (loss) from investment operations
Net investment income (loss) (d)		$0.02			$0.06			$0.03			$0.05	(c)		$0.02			$0.06
Net realized and unrealized gain (loss)		5.12			(1.85	)		5.94			2.03			(0.16	)		2.63
Total from investment operations		$5.14			$(1.79	)		$5.97			$2.08			$(0.14	)		$2.69
Less distributions declared to shareholders
From net investment income		$(0.03	)		$(0.03	)		$(0.06	)		$(0.05	)		$(0.05	)		$(0.04	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.32	)		$(3.44	)		$(2.09	)		$(1.50	)		$(1.43	)		$(1.72	)
Net asset value, end of period (x)		$30.06			$25.24			$30.47			$26.59			$26.01			$27.58
Total return (%) (r)(s)(t)(x)		20.35	(n)		(6.03	)		22.58			7.98	(c)		(0.51	)		10.16
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.47	(a)		1.46			1.47			1.48	(c)		1.47			1.47
Expenses after expense reductions (f)		N/A			N/A			N/A			1.48	(c)		1.47			1.47
Net investment income (loss)		0.13	(a)		0.18			0.11			0.21	(c)		0.07			0.20
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$5,588			$5,066			$7,058			$7,879			$9,516			$9,803

See Notes to Financial Statements

18

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class R2				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$25.42			$30.69			$26.77			$26.17			$27.74			$26.75
Income (loss) from investment operations
Net investment income (loss) (d)		$0.09			$0.22			$0.18			$0.19	(c)		$0.16			$0.19
Net realized and unrealized gain (loss)		5.16			(1.88	)		5.99			2.05			(0.17	)		2.65
Total from investment operations		$5.25			$(1.66	)		$6.17			$2.24			$(0.01	)		$2.84
Less distributions declared to shareholders
From net investment income		$(0.06	)		$(0.20	)		$(0.22	)		$(0.19	)		$(0.18	)		$(0.17	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.35	)		$(3.61	)		$(2.25	)		$(1.64	)		$(1.56	)		$(1.85	)
Net asset value, end of period (x)		$30.32			$25.42			$30.69			$26.77			$26.17			$27.74
Total return (%) (r)(s)(t)(x)		20.66	(n)		(5.56	)		23.19			8.54	(c)		(0.03	)		10.68
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		0.97	(a)		0.96			0.97			0.97	(c)		0.97			0.97
Expenses after expense reductions (f)		N/A			N/A			N/A			0.97	(c)		0.97			0.97
Net investment income (loss)		0.63	(a)		0.69			0.61			0.71	(c)		0.57			0.70
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$127,592			$122,858			$155,976			$153,518			$177,562			$208,074

See Notes to Financial Statements

19

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class R3				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$26.52			$31.87			$27.72			$27.05			$28.61			$27.53
Income (loss) from investment operations
Net investment income (loss) (d)		$0.13			$0.31			$0.27			$0.26	(c)		$0.24			$0.27
Net realized and unrealized gain (loss)		5.40			(1.97	)		6.21			2.12			(0.17	)		2.73
Total from investment operations		$5.53			$(1.66	)		$6.48			$2.38			$0.07			$3.00
Less distributions declared to shareholders
From net investment income		$(0.08	)		$(0.28	)		$(0.30	)		$(0.26	)		$(0.25	)		$(0.24	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.37	)		$(3.69	)		$(2.33	)		$(1.71	)		$(1.63	)		$(1.92	)
Net asset value, end of period (x)		$31.68			$26.52			$31.87			$27.72			$27.05			$28.61
Total return (%) (r)(s)(t)(x)		20.86	(n)		(5.36	)		23.50			8.78	(c)		0.26			10.97
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		0.72	(a)		0.71			0.72			0.72	(c)		0.72			0.72
Expenses after expense reductions (f)		N/A			0.71			0.72			0.72	(c)		0.72			0.72
Net investment income (loss)		0.88	(a)		0.94			0.86			0.96	(c)		0.82			0.95
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$294,668			$261,258			$318,535			$313,515			$333,089			$390,209

See Notes to Financial Statements

20

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class R4				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$27.04			$32.42			$28.16			$27.45			$29.02			$27.89
Income (loss) from investment operations
Net investment income (loss) (d)		$0.17			$0.39			$0.35			$0.33	(c)		$0.31			$0.35
Net realized and unrealized gain (loss)		5.50			(1.99	)		6.32			2.16			(0.17	)		2.77
Total from investment operations		$5.67			$(1.60	)		$6.67			$2.49			$0.14			$3.12
Less distributions declared to shareholders
From net investment income		$(0.10	)		$(0.37	)		$(0.38	)		$(0.33	)		$(0.33	)		$(0.31	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.39	)		$(3.78	)		$(2.41	)		$(1.78	)		$(1.71	)		$(1.99	)
Net asset value, end of period (x)		$32.32			$27.04			$32.42			$28.16			$27.45			$29.02
Total return (%) (r)(s)(t)(x)		20.97	(n)		(5.10	)		23.84			9.06	(c)		0.48			11.28
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		0.47	(a)		0.46			0.47			0.47	(c)		0.46			0.47
Expenses after expense reductions (f)		N/A			N/A			N/A			0.47	(c)		0.46			0.47
Net investment income (loss)		1.13	(a)		1.19			1.11			1.20	(c)		1.07			1.21
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$73,098			$60,904			$69,546			$54,737			$82,539			$94,154

See Notes to Financial Statements

21

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class R6				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$25.95			$31.28			$27.24			$26.61			$28.18			$27.14
Income (loss) from investment operations
Net investment income (loss) (d)		$0.18			$0.41			$0.35			$0.35	(c)		$0.33			$0.36
Net realized and unrealized gain (loss)		5.29			(1.93	)		6.13			2.08			(0.17	)		2.70
Total from investment operations		$5.47			$(1.52	)		$6.48			$2.43			$0.16			$3.06
Less distributions declared to shareholders
From net investment income		$(0.11	)		$(0.40	)		$(0.41	)		$(0.35	)		$(0.35	)		$(0.34	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.40	)		$(3.81	)		$(2.44	)		$(1.80	)		$(1.73	)		$(2.02	)
Net asset value, end of period (x)		$31.02			$25.95			$31.28			$27.24			$26.61			$28.18
Total return (%) (r)(s)(t)(x)		21.06	(n)		(5.03	)		23.93			9.15	(c)		0.58			11.36
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		0.39	(a)		0.38			0.39			0.39	(c)		0.38			0.38
Expenses after expense reductions (f)		N/A			N/A			N/A			0.39	(c)		0.38			0.38
Net investment income (loss)		1.21	(a)		1.28			1.12			1.30	(c)		1.16			1.29
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$875,364			$905,246			$814,161			$114,700			$103,806			$68,711

See Notes to Financial Statements

22

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class 529A				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$26.05			$31.38			$27.33			$26.70			$28.28			$27.24
Income (loss) from investment operations
Net investment income (loss) (d)		$0.12			$0.29			$0.25			$0.25	(c)		$0.23			$0.26
Net realized and unrealized gain (loss)		5.30			(1.92	)		6.13			2.09			(0.18	)		2.70
Total from investment operations		$5.42			$(1.63	)		$6.38			$2.34			$0.05			$2.96
Less distributions declared to shareholders
From net investment income		$(0.08	)		$(0.29	)		$(0.30	)		$(0.26	)		$(0.25	)		$(0.24	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.37	)		$(3.70	)		$(2.33	)		$(1.71	)		$(1.63	)		$(1.92	)
Net asset value, end of period (x)		$31.10			$26.05			$31.38			$27.33			$26.70			$28.28
Total return (%) (r)(s)(t)(x)		20.81	(n)		(5.37	)		23.47			8.76	(c)		0.19			10.96
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		0.77	(a)		0.76			0.82			0.82	(c)		0.82			0.82
Expenses after expense reductions (f)		0.75	(a)		0.75			0.76			0.75	(c)		0.74			0.74
Net investment income (loss)		0.85	(a)		0.91			0.84			0.93	(c)		0.80			0.94
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$15,087			$12,747			$11,725			$8,827			$7,161			$5,947

See Notes to Financial Statements

23

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class 529B				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$24.43			$29.68			$25.95			$25.44			$27.03			$26.12
Income (loss) from investment operations
Net investment income (loss) (d)		$0.01			$0.24			$0.02			$0.12	(c)		$0.01			$0.05
Net realized and unrealized gain (loss)		4.96			(1.81	)		5.81			1.98			(0.15	)		2.58
Total from investment operations		$4.97			$(1.57	)		$5.83			$2.10			$(0.14	)		$2.63
Less distributions declared to shareholders
From net investment income		$(0.03	)		$(0.27	)		$(0.07	)		$(0.14	)		$(0.07	)		$(0.04	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.32	)		$(3.68	)		$(2.10	)		$(1.59	)		$(1.45	)		$(1.72	)
Net asset value, end of period (x)		$29.08			$24.43			$29.68			$25.95			$25.44			$27.03
Total return (%) (r)(s)(t)(x)		20.35	(n)		(5.45	)		22.57			8.26	(c)		(0.53	)		10.14
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.51	(a)		0.86			1.57			1.27	(c)		1.57			1.57
Expenses after expense reductions (f)		1.50	(a)		0.84			1.51			1.20	(c)		1.50			1.50
Net investment income (loss)		0.10	(a)		0.80			0.08			0.48	(c)		0.04			0.18
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$425			$358			$464			$475			$438			$363

See Notes to Financial Statements

24

Financial Highlights – continued

	Six months ended 6/30/19			Year ended
Class 529C				12/31/18			12/31/17			12/31/16			12/31/15			12/31/14
	(unaudited)
Net asset value, beginning of period		$24.08			$29.28			$25.65			$25.16			$26.75			$25.85
Income (loss) from investment operations
Net investment income (loss) (d)		$0.01			$0.04			$0.02			$0.04	(c)		$0.01			$0.04
Net realized and unrealized gain (loss)		4.89			(1.77	)		5.73			1.95			(0.17	)		2.57
Total from investment operations		$4.90			$(1.73	)		$5.75			$1.99			$(0.16	)		$2.61
Less distributions declared to shareholders
From net investment income		$(0.03	)		$(0.06	)		$(0.09	)		$(0.05	)		$(0.05	)		$(0.03	)
From net realized gain		(0.29	)		(3.41	)		(2.03	)		(1.45	)		(1.38	)		(1.68	)
Total distributions declared to shareholders		$(0.32	)		$(3.47	)		$(2.12	)		$(1.50	)		$(1.43	)		$(1.71	)
Net asset value, end of period (x)		$28.66			$24.08			$29.28			$25.65			$25.16			$26.75
Total return (%) (r)(s)(t)(x)		20.34	(n)		(6.08	)		22.54			7.91	(c)		(0.58	)		10.16
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.51	(a)		1.51			1.57			1.57	(c)		1.57			1.57
Expenses after expense reductions (f)		1.51	(a)		1.51			1.52			1.52	(c)		1.51			1.52
Net investment income (loss)		0.09	(a)		0.14			0.07			0.16	(c)		0.03			0.16
Portfolio turnover		7	(n)		13			12			12			18			18
Net assets at end of period (000 omitted)		$3,523			$3,117			$3,787			$2,870			$2,817			$2,683

(a) Annualized.

(c) Amount reflects a one-time reimbursement of expenses by the custodian (or former custodian) without which net investment income and performance would be lower and expenses would be higher.

(d) Per share data is based on average shares outstanding.

(f) Ratios do not reflect reductions from fees paid indirectly, if applicable.

(n) Not annualized.

(r) Certain expenses have been reduced without which performance would have been lower.

(s) From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

(t) Total returns do not include any applicable sales charges.

(x) The net asset values and total returns have been calculated on net assets which include adjustments made in accordance with U.S. generally accepted accounting principles required at period end for financial reporting purposes.

See Notes to Financial Statements

25

NOTES TO FINANCIAL STATEMENTS

(unaudited)

(1) Business and Organization

Massachusetts Investors Trust (the fund) is organized as a Massachusetts business trust and is registered under the Investment Company Act of 1940, as amended, as a diversified open-end management investment company.

The fund is an investment company and accordingly follows the investment company accounting and reporting guidance of the Financial Accounting Standards Board (FASB) Accounting Standards Codification Topic 946 Financial Services – Investment Companies.

(2) Significant Accounting Policies

General – The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of increases and decreases in net assets from operations during the reporting period. Actual results could differ from those estimates. In the preparation of these financial statements, management has evaluated subsequent events occurring after the date of the fund’s Statement of Assets and Liabilities through the date that the financial statements were issued.

Balance Sheet Offsetting – The fund’s accounting policy with respect to balance sheet offsetting is that, absent an event of default by the counterparty or a termination of the agreement, the International Swaps and Derivatives Association (ISDA) Master Agreement, or similar agreement, does not result in an offset of reported amounts of financial assets and financial liabilities in the Statement of Assets and Liabilities across transactions between the fund and the applicable counterparty. The fund’s right to setoff may be restricted or prohibited by the bankruptcy or insolvency laws of the particular jurisdiction to which a specific master netting agreement counterparty is subject. Balance sheet offsetting disclosures, to the extent applicable to the fund, have been included in the fund’s Significant Accounting Policies note under the captions for each of the fund’s in-scope financial instruments and transactions.

Investment Valuations – Equity securities, including restricted equity securities, are generally valued at the last sale or official closing price on their primary market or exchange as provided by a third-party pricing service. Equity securities, for which there were no sales reported that day, are generally valued at the last quoted daily bid quotation on their primary market or exchange as provided by a third-party pricing service. Short-term instruments with a maturity at issuance of 60 days or less may be valued at amortized cost, which approximates market value. Open-end investment companies are generally valued at net asset value per share. Securities and other assets generally valued on the basis of information from a third-party pricing service may also be valued at a broker/dealer bid quotation. In determining values, third-party pricing services can utilize both transaction data and market information such as yield, quality, coupon rate, maturity, type of issue, trading characteristics, and other market data. The values of foreign securities and other assets and liabilities expressed in foreign currencies are converted to U.S. dollars using the mean of bid and asked prices for rates provided by a third-party pricing service.

26

Notes to Financial Statements (unaudited) – continued

The Board of Trustees has delegated primary responsibility for determining or causing to be determined the value of the fund’s investments (including any fair valuation) to the adviser pursuant to valuation policies and procedures approved by the Board. If the adviser determines that reliable market quotations are not readily available, investments are valued at fair value as determined in good faith by the adviser in accordance with such procedures under the oversight of the Board of Trustees. Under the fund’s valuation policies and procedures, market quotations are not considered to be readily available for most types of debt instruments and floating rate loans and many types of derivatives. These investments are generally valued at fair value based on information from third-party pricing services. In addition, investments may be valued at fair value if the adviser determines that an investment’s value has been materially affected by events occurring after the close of the exchange or market on which the investment is principally traded (such as foreign exchange or market) and prior to the determination of the fund’s net asset value, or after the halt of trading of a specific security where trading does not resume prior to the close of the exchange or market on which the security is principally traded. Events that occur after foreign markets close (such as developments in foreign markets and significant movements in the U.S. markets) and prior to the determination of the fund’s net asset value may be deemed to have a material effect on the value of securities traded in foreign markets. Accordingly, the fund’s foreign equity securities may often be valued at fair value. The adviser generally relies on third-party pricing services or other information (such as the correlation with price movements of similar securities in the same or other markets; the type, cost and investment characteristics of the security; the business and financial condition of the issuer; and trading and other market data) to assist in determining whether to fair value and at what value to fair value an investment. The value of an investment for purposes of calculating the fund’s net asset value can differ depending on the source and method used to determine value. When fair valuation is used, the value of an investment used to determine the fund’s net asset value may differ from quoted or published prices for the same investment. There can be no assurance that the fund could obtain the fair value assigned to an investment if it were to sell the investment at the same time at which the fund determines its net asset value per share.

Various inputs are used in determining the value of the fund’s assets or liabilities. These inputs are categorized into three broad levels. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an investment’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The fund’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the investment. Level 1 includes unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 includes other significant observable market-based inputs (including quoted prices for similar securities, interest rates, prepayment speed, and credit risk). Level 3 includes

27

Notes to Financial Statements (unaudited) – continued

unobservable inputs, which may include the adviser’s own assumptions in determining the fair value of investments. The following is a summary of the levels used as of June 30, 2019 in valuing the fund’s assets or liabilities:

Financial Instruments	Level 1		Level 2		Level 3		Total
Equity Securities		$5,741,101,224		$—		$—		$5,741,101,224
Mutual Funds		40,726,973		—		—		40,726,973
Total		$5,781,828,197		$—		$—		$5,781,828,197

For further information regarding security characteristics, see the Portfolio of Investments.

Foreign Currency Translation – Purchases and sales of foreign investments, income, and expenses are converted into U.S. dollars based upon currency exchange rates prevailing on the respective dates of such transactions or on the reporting date for foreign denominated receivables and payables. Gains and losses attributable to foreign currency exchange rates on sales of securities are recorded for financial statement purposes as net realized gains and losses on investments. Gains and losses attributable to foreign exchange rate movements on receivables, payables, income and expenses are recorded for financial statement purposes as foreign currency transaction gains and losses. That portion of both realized and unrealized gains and losses on investments that results from fluctuations in foreign currency exchange rates is not separately disclosed.

Security Loans – Under its Securities Lending Agency Agreement with the fund, State Street Bank and Trust Company, as lending agent, loans the securities of the fund to certain qualified institutions (the “Borrowers”) approved by the fund. Security loans can be terminated at the discretion of either the lending agent or the fund and the related securities must be returned within the earlier of the standard trade settlement period for such securities or within three business days. The loans are collateralized by cash and/or U.S. Treasury and federal agency obligations in an amount typically at least equal to the market value of the securities loaned. On loans collateralized by cash, the cash collateral is invested in a money market fund. The market value of the loaned securities is determined at the close of business of the fund and any additional required collateral is delivered to the fund on the next business day. The lending agent provides the fund with indemnification against Borrower default. In the event of Borrower default, the lending agent will, for the benefit of the fund, either purchase securities identical to those loaned or, when such purchase is commercially impracticable, pay the fund the market value of the loaned securities. In return, the lending agent assumes the fund’s rights to the related collateral. If the collateral value is less than the cost to purchase identical securities, the lending agent is responsible for the shortfall, but only to the extent that such shortfall is not due to a decline in collateral value resulting from collateral reinvestment for which the fund bears the risk of loss. A portion of the income generated upon investment of the collateral is remitted to the Borrowers, and the remainder is allocated between the fund and the lending agent. On loans collateralized by U.S. Treasury and/or federal agency obligations, a fee is received from the Borrower, and is allocated between the fund and the lending agent. Income from securities lending is separately reported in the Statement of Operations. The dividend

28

Notes to Financial Statements (unaudited) – continued

and interest income earned on the securities loaned is accounted for in the same manner as other dividend and interest income. At June 30, 2019, there were no securities on loan or collateral outstanding.

Indemnifications – Under the fund’s organizational documents, its officers and Trustees may be indemnified against certain liabilities and expenses arising out of the performance of their duties to the fund. Additionally, in the normal course of business, the fund enters into agreements with service providers that may contain indemnification clauses. The fund’s maximum exposure under these agreements is unknown as this would involve future claims that may be made against the fund that have not yet occurred.

Investment Transactions and Income – Investment transactions are recorded on the trade date. Interest income is recorded on the accrual basis. Dividends received in cash are recorded on the ex-dividend date. Certain dividends from foreign securities will be recorded when the fund is informed of the dividend if such information is obtained subsequent to the ex-dividend date. Dividend payments received in additional securities are recorded on the ex-dividend date in an amount equal to the value of the security on such date.

The fund may receive proceeds from litigation settlements. Any proceeds received from litigation involving portfolio holdings are reflected in the Statement of Operations in realized gain/loss if the security has been disposed of by the fund or in unrealized gain/loss if the security is still held by the fund. Any other proceeds from litigation not related to portfolio holdings are reflected as other income in the Statement of Operations.

Tax Matters and Distributions – The fund intends to qualify as a regulated investment company, as defined under Subchapter M of the Internal Revenue Code, and to distribute all of its taxable income, including realized capital gains. As a result, no provision for federal income tax is required. The fund’s federal tax returns, when filed, will remain subject to examination by the Internal Revenue Service for a three year period. Management has analyzed the fund’s tax positions taken on federal and state tax returns for all open tax years and does not believe that there are any uncertain tax positions that require recognition of a tax liability. Foreign taxes, if any, have been accrued by the fund in the accompanying financial statements in accordance with the applicable foreign tax law. Foreign income taxes may be withheld by certain countries in which the fund invests. Additionally, capital gains realized by the fund on securities issued in or by certain foreign countries may be subject to capital gains tax imposed by those countries.

Distributions to shareholders are recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from U.S. generally accepted accounting principles. Certain capital accounts in the financial statements are periodically adjusted for permanent differences in order to reflect their tax character. These adjustments have no impact on net assets or net asset value per share. Temporary differences which arise from recognizing certain items of income, expense, gain or loss in different periods for financial statement and tax purposes will reverse at some time in the future. Distributions in excess of net

29

Notes to Financial Statements (unaudited) – continued

investment income or net realized gains are temporary overdistributions for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax purposes.

Book/tax differences primarily relate to wash sale loss deferrals, treating a portion of the proceeds from redemptions as a distribution for tax purposes, and partnership adjustments.

The tax character of distributions made during the current period will be determined at fiscal year end. The tax character of distributions declared to shareholders for the last fiscal year is as follows:

	Year ended 12/31/18
Ordinary income (including any short-term capital gains)		$62,499,249
Long-term capital gains		587,467,733
Total distributions		$649,966,982

The federal tax cost and the tax basis components of distributable earnings were as follows:

As of 6/30/19
Cost of investments	$3,117,313,425
Gross appreciation	2,756,849,061
Gross depreciation	(92,334,289	)
Net unrealized appreciation (depreciation)	$2,664,514,772
As of 12/31/18
Undistributed ordinary income	8,872,468
Undistributed long-term capital gain	51,114,998
Post-October capital loss deferral	(3,622,532	)
Other temporary differences	13,525,832
Net unrealized appreciation (depreciation)	1,807,911,618

The aggregate cost above includes prior fiscal year end tax adjustments, if applicable.

Multiple Classes of Shares of Beneficial Interest – The fund offers multiple classes of shares, which differ in their respective distribution, service, and program manager fees. The fund’s income, realized and unrealized gain (loss), and common expenses are allocated to shareholders based on the daily net assets of each class. Dividends are declared separately for each class. Differences in per share dividend rates are generally due to differences in separate class expenses. Class B and Class 529B shares will convert to Class A and Class 529A shares, respectively, approximately eight years after purchase. Class C and Class 529C shares will convert to Class A and Class 529A shares,

30

Notes to Financial Statements (unaudited) – continued

respectively, approximately ten years after purchase. The fund’s distributions declared to shareholders as reported in the Statements of Changes in Net Assets are presented by class as follows:

	From net investment income				From net realized gain
	Six months ended 6/30/19		Year ended 12/31/18		Six months ended 6/30/19		Year ended 12/31/18
Class A		$9,508,162		$31,452,602		$33,201,832		$362,259,630
Class B		36,930		64,330		507,390		6,342,332
Class C		149,357		196,839		1,679,312		19,786,287
Class I		1,430,566		4,818,017		4,140,654		46,188,369
Class R1		4,868		5,030		53,394		604,310
Class R2		259,194		889,991		1,209,755		14,728,481
Class R3		758,121		2,550,919		2,679,124		30,239,654
Class R4		223,661		749,145		649,246		6,849,465
Class R6		2,965,699		13,792,816		8,141,579		106,429,402
Class 529A		38,129		120,781		139,164		1,456,465
Class 529B		456		3,507		4,198		44,063
Class 529C		3,467		6,412		35,287		388,135
Total		$15,378,610		$54,650,389		$52,440,935		$595,316,593

(3) Transactions with Affiliates

Investment Adviser – The fund has an investment advisory agreement with MFS to provide overall investment management and related administrative services and facilities to the fund. The management fee is computed daily and paid monthly at an annual rate of 0.33% of the fund’s average daily net assets.

Distributor – MFS Fund Distributors, Inc. (MFD), a wholly-owned subsidiary of MFS, as distributor, received $218,938 and $3,923 for the six months ended June 30, 2019, as its portion of the initial sales charge on sales of Class A and Class 529A shares of the fund, respectively.

The Board of Trustees has adopted a distribution plan for certain share classes pursuant to Rule 12b-1 of the Investment Company Act of 1940.

The fund’s distribution plan provides that the fund will pay MFD for services provided by MFD and financial intermediaries in connection with the distribution and servicing of certain share classes. One component of the plan is a distribution fee paid to MFD and another component of the plan is a service fee paid to MFD. MFD may subsequently pay all, or a portion, of the distribution and/or service fees to financial intermediaries.

31

Notes to Financial Statements (unaudited) – continued

Distribution Plan Fee Table:

	Distribution Fee Rate (d)		Service Fee Rate (d)		Total Distribution Plan (d)		Annual Effective Rate (e)		Distribution and Service Fee
Class A		—		0.25%		0.25%		0.23%		$4,364,693
Class B		0.75%		0.25%		1.00%		0.99%		275,781
Class C		0.75%		0.25%		1.00%		1.00%		871,152
Class R1		0.75%		0.25%		1.00%		1.00%		27,552
Class R2		0.25%		0.25%		0.50%		0.50%		317,638
Class R3		—		0.25%		0.25%		0.25%		344,290
Class 529A		—		0.25%		0.25%		0.24%		17,871
Class 529B		0.75%		0.25%		1.00%		0.99%		2,008
Class 529C		0.75%		0.25%		1.00%		1.00%		17,109
Total Distribution and Service Fees										$6,238,094

(d) In accordance with the distribution plan for certain classes, the fund pays distribution and/or service fees equal to these annual percentage rates of each class’s average daily net assets. The distribution and service fee rates disclosed by class represent the current rates in effect at the end of the reporting period. Any rate changes, if applicable, are detailed below.

(e) The annual effective rates represent actual fees incurred under the distribution plan for the six months ended June 30, 2019 based on each class’s average daily net assets. MFD has voluntarily agreed to rebate a portion of each class’s 0.25% service fee attributable to accounts for which MFD retains the 0.25% service fee except for accounts attributable to MFS or its affiliates’ seed money. For the six months ended June 30, 2019, this rebate amounted to $370,572, $1,373, $939, $879, $22, and $21 for Class A, Class B, Class C, Class 529A, Class 529B, and Class 529C, respectively, and is included in the reduction of total expenses in the Statement of Operations.

Certain Class A shares are subject to a contingent deferred sales charge (CDSC) in the event of a shareholder redemption within 18 months of purchase. Class B and Class 529B shares are subject to a CDSC in the event of a shareholder redemption within six years of purchase. Class C and Class 529C shares are subject to a CDSC in the event of a shareholder redemption within 12 months of purchase. All contingent deferred sales charges are paid to MFD and during the six months ended June 30, 2019, were as follows:

	Amount
Class A		$5,919
Class B		31,065
Class C		3,762
Class 529B		—
Class 529C		51

The fund has entered into and may from time to time enter into contracts with program managers and other parties which administer the tuition programs through which an investment in the fund’s 529 share classes is made. The fund has entered into an agreement with MFD pursuant to which MFD receives an annual fee of up to 0.05% of the average daily net assets attributable to each 529 share class. The services provided by MFD, or a third party with which MFD contracts, include recordkeeping and tax reporting and account services, as well as services designed to maintain the

32

Notes to Financial Statements (unaudited) – continued

program’s compliance with the Internal Revenue Code and other regulatory requirements. Program manager fees for the six months ended June 30, 2019, were as follows:

	Fee
Class 529A		$3,573
Class 529B		100
Class 529C		854
Total Program Manager Fees		$4,527

Shareholder Servicing Agent – MFS Service Center, Inc. (MFSC), a wholly-owned subsidiary of MFS, receives a fee from the fund for its services as shareholder servicing agent calculated as a percentage of the average daily net assets of the fund as determined periodically under the supervision of the fund’s Board of Trustees. For the six months ended June 30, 2019, the fee was $372,231, which equated to 0.0134% annually of the fund’s average daily net assets. MFSC also receives payment from the fund for out-of-pocket expenses, sub-accounting and other shareholder servicing costs which may be paid to affiliated and unaffiliated service providers. Class R6 shares do not incur sub-accounting fees. For the six months ended June 30, 2019, these out-of-pocket expenses, sub-accounting and other shareholder servicing costs amounted to $2,165,177.

Administrator – MFS provides certain financial, legal, shareholder communications, compliance, and other administrative services to the fund. Under an administrative services agreement, the fund reimburses MFS the costs incurred to provide these services. The fund is charged an annual fixed amount of $17,500 plus a fee based on average daily net assets. The administrative services fee incurred for the six months ended June 30, 2019 was equivalent to an annual effective rate of 0.0108% of the fund’s average daily net assets.

Trustees’ and Officers’ Compensation – The fund pays compensation to independent Trustees in the form of a retainer, attendance fees, and additional compensation to Board and Committee chairpersons. The fund does not pay compensation directly to Trustees or officers of the fund who are also officers of the investment adviser, all of whom receive remuneration from MFS for their services to the fund. Certain officers and Trustees of the fund are officers or directors of MFS, MFD, and MFSC.

Prior to December 31, 2001, the fund had an unfunded defined benefit plan (“DB plan”) for independent Trustees. As of December 31, 2001, the Board took action to terminate the DB plan with respect to then-current and any future independent Trustees, such that the DB plan covers only certain of those former independent Trustees who retired on or before December 31, 2001. Effective January 1, 2002, accrued benefits under the DB plan for then-current independent Trustees who continued were credited to an unfunded retirement deferral plan (the “Retirement Deferral plan”), which was established for and exists solely with respect to these credited amounts, and is not available for other deferrals by these or other independent Trustees. Although the Retirement Deferral plan is unfunded, amounts deferred under the plan are periodically adjusted for investment experience as if they had been invested in shares of the fund. The DB plan resulted in a net decrease in

33

Notes to Financial Statements (unaudited) – continued

pension expense of $594 and the Retirement Deferral plan, which terminated on December 31, 2018, resulted in a net decrease in expense of $4,237. Both amounts are included in “Independent Trustees’ compensation” in the Statement of Operations for the six months ended June 30, 2019. The liability for deferred retirement benefits payable to those former independent Trustees under the DB Plan amounted to $10,684 at June 30, 2019, and is included in “Payable for independent Trustees’ compensation” in the Statement of Assets and Liabilities.

Other – This fund and certain other funds managed by MFS (the funds) had entered into a service agreement (the ISO Agreement) which provided for payment of fees solely by the funds to Tarantino LLC in return for the provision of services of an Independent Senior Officer (ISO) for the funds. Frank L. Tarantino served as the ISO and was an officer of the funds and the sole member of Tarantino LLC. Effective June 30, 2019, Mr. Tarantino retired from his position as ISO for the funds, and the ISO Agreement was terminated. For the six months ended June 30, 2019, the fee paid by the fund under this agreement was $6,684 and is included in “Miscellaneous” expense in the Statement of Operations. MFS had agreed to bear all expenses associated with office space, other administrative support, and supplies provided to the ISO.

The fund invests in the MFS Institutional Money Market Portfolio which is managed by MFS and seeks current income consistent with preservation of capital and liquidity. This money market fund does not pay a management fee to MFS.

The fund is permitted to engage in purchase and sale transactions with funds and accounts for which MFS serves as investment adviser or sub-adviser (“cross-trades”) pursuant to a policy adopted by the Board of Trustees. This policy has been designed to ensure that cross-trades conducted by the fund comply with Rule 17a-7 under the Investment Company Act of 1940. During the six months ended June 30, 2019, the fund engaged in purchase and sale transactions pursuant to this policy, which amounted to $776,849 and $14,109,657, respectively. The sales transactions resulted in net realized gains (losses) of $(1,645,194).

The adviser has voluntarily undertaken to reimburse the fund from its own resources on a quarterly basis for the cost of investment research embedded in the cost of the fund’s securities trades. This agreement may be rescinded at any time. For the six months ended June 30, 2019, this reimbursement amounted to $89,987, which is included in “Other” income in the Statement of Operations.

(4) Portfolio Securities

For the six months ended June 30, 2019, purchases and sales of investments, other than short-term obligations, aggregated $358,689,744 and $701,105,279, respectively.

34

Notes to Financial Statements (unaudited) – continued

(5) Shares of Beneficial Interest

The fund’s Declaration of Trust permits the Trustees to issue an unlimited number of full and fractional shares of beneficial interest. Transactions in fund shares were as follows:

	Six months ended 6/30/19				Year ended 12/31/18
	Shares		Amount		Shares		Amount
Shares sold
Class A		3,308,798		$100,123,004		9,968,750		$319,019,860
Class B		46,543		1,346,912		146,719		4,624,694
Class C		207,159		5,925,473		697,149		21,348,573
Class I		1,562,333		46,414,327		4,849,977		153,835,750
Class R1		11,510		324,253		19,461		597,918
Class R2		171,274		4,904,564		424,924		13,171,048
Class R3		742,552		22,669,373		1,036,415		33,736,651
Class R4		192,605		5,908,170		434,562		14,398,696
Class R6		3,531,243		103,137,432		28,899,695		922,773,193
Class 529A		29,635		860,693		93,081		2,945,021
Class 529B		950		26,733		1,283		38,455
Class 529C		5,164		138,231		12,355		367,216
		9,809,766		$291,779,165		46,584,371		$1,486,857,075
Shares issued to shareholders in reinvestment of distributions
Class A		1,196,749		$38,296,523		12,911,708		$352,277,898
Class B		17,165		531,005		236,428		6,237,259
Class C		56,092		1,697,335		718,168		18,540,338
Class I		162,864		5,052,042		1,748,196		46,236,369
Class R1		1,938		58,262		23,738		609,340
Class R2		47,103		1,428,165		578,866		14,985,813
Class R3		108,499		3,437,245		1,213,716		32,790,573
Class R4		27,008		872,907		275,735		7,598,610
Class R6		340,414		10,559,651		4,356,847		115,755,820
Class 529A		5,701		177,293		59,461		1,577,246
Class 529B		160		4,654		1,914		47,570
Class 529C		1,352		38,754		16,119		394,547
		1,965,045		$62,153,836		22,140,896		$597,051,383

35

Notes to Financial Statements (unaudited) – continued

	Six months ended 6/30/19						Year ended 12/31/18
	Shares			Amount			Shares			Amount
Shares reacquired
Class A		(6,617,367	)		$(201,415,199	)		(15,490,179	)		$(496,979,714	)
Class B		(344,887	)		(10,162,884	)		(634,755	)		(20,022,538	)
Class C		(840,673	)		(24,243,268	)		(5,026,537	)		(154,456,184	)
Class I		(1,850,204	)		(54,118,408	)		(32,752,467	)		(1,042,200,511	)
Class R1		(28,327	)		(820,091	)		(74,072	)		(2,285,790	)
Class R2		(843,860	)		(23,958,177	)		(1,252,339	)		(38,975,699	)
Class R3		(1,398,301	)		(40,917,745	)		(2,395,341	)		(77,248,127	)
Class R4		(210,415	)		(6,458,228	)		(602,960	)		(19,848,471	)
Class R6		(10,527,299	)		(311,645,010	)		(24,404,803	)		(780,723,382	)
Class 529A		(39,544	)		(1,171,270	)		(36,906	)		(1,180,273	)
Class 529B		(1,152	)		(32,410	)		(4,162	)		(126,856	)
Class 529C		(13,050	)		(355,254	)		(28,364	)		(838,751	)
		(22,715,079	)		$(675,297,944	)		(82,702,885	)		$(2,634,886,296	)
Net change
Class A		(2,111,820	)		$(62,995,672	)		7,390,279			$174,318,044
Class B		(281,179	)		(8,284,967	)		(251,608	)		(9,160,585	)
Class C		(577,422	)		(16,620,460	)		(3,611,220	)		(114,567,273	)
Class I		(125,007	)		(2,652,039	)		(26,154,294	)		(842,128,392	)
Class R1		(14,879	)		(437,576	)		(30,873	)		(1,078,532	)
Class R2		(625,483	)		(17,625,448	)		(248,549	)		(10,818,838	)
Class R3		(547,250	)		(14,811,127	)		(145,210	)		(10,720,903	)
Class R4		9,198			322,849			107,337			2,148,835
Class R6		(6,655,642	)		(197,947,927	)		8,851,739			257,805,631
Class 529A		(4,208	)		(133,284	)		115,636			3,341,994
Class 529B		(42	)		(1,023	)		(965	)		(40,831	)
Class 529C		(6,534	)		(178,269	)		110			(76,988	)
		(10,940,268	)		$(321,364,943	)		(13,977,618	)		$(550,977,838	)

Class T shares were not publicly available for sale during the period. Please see the fund’s prospectus for details.

Effective June 1, 2019, purchases of the fund’s Class B and Class 529B shares are closed to new and existing investors subject to certain exceptions. Please see the fund’s prospectus for details.

(6) Line of Credit

The fund and certain other funds managed by MFS participate in a $1.25 billion unsecured committed line of credit, subject to a $1 billion sublimit, provided by a syndicate of banks under a credit agreement. Borrowings may be made for temporary financing needs. Interest is charged to each fund, based on its borrowings, generally at a rate equal to the highest of one month LIBOR, the Federal Funds Effective Rate and the Overnight Bank Funding Rate, plus an agreed upon spread. A commitment fee, based on the average daily, unused portion of the committed line of credit, is allocated among the participating funds. In addition, the fund and other funds managed by MFS

36

Notes to Financial Statements (unaudited) – continued

have established unsecured uncommitted borrowing arrangements with certain banks for temporary financing needs. Interest is charged to each fund, based on its borrowings, at rates equal to customary reference rates plus an agreed upon spread. For the six months ended June 30, 2019, the fund’s commitment fee and interest expense were $16,961 and $0, respectively, and are included in “Miscellaneous” expense in the Statement of Operations.

(7) Investments in Affiliated Issuers

An affiliated issuer may be considered one in which the fund owns 5% or more of the outstanding voting securities, or a company which is under common control. For the purposes of this report, the following were affiliated issuers:

Affiliated Issuers	Beginning Value		Purchases		Sales Proceeds		Realized Gain (Loss)		Change in Unrealized Appreciation or Depreciation		Ending Value
MFS Institutional Money Market Portfolio		$46,944,516		$241,949,730		$248,178,145		$2,983		$7,889		$40,726,973
Affiliated Issuers									Dividend Income		Capital Gain Distributions
MFS Institutional Money Market Portfolio										$541,526		$—

37

PROXY VOTING POLICIES AND INFORMATION

MFS votes proxies on behalf of the fund pursuant to proxy voting policies and procedures that are available without charge, upon request, by calling 1-800-225-2606, by visiting mfs.com/proxyvoting, or by visiting the SEC’s Web site at http://www.sec.gov.

Information regarding how the fund voted proxies relating to portfolio securities during the most recent twelve-month period ended June 30 is available by August 31 of each year without charge by visiting mfs.com/proxyvoting, or by visiting the SEC’s Web site at http://www.sec.gov.

QUARTERLY PORTFOLIO DISCLOSURE

The fund files a complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-Q or as an exhibit to its reports on Form N-PORT (for first and third fiscal quarters ending March 31, 2019 or after). The fund’s Form N-Q or Form N-PORT reports are available on the SEC’s website at http://www.sec.gov. A shareholder can obtain the portfolio holdings report for the first and third quarters of the fund’s fiscal year at mfs.com/openendfunds by choosing the fund’s name and then selecting the “Resources” tab and clicking on “Prospectus and Reports”.

FURTHER INFORMATION

From time to time, MFS may post important information about the fund or the MFS funds on the MFS web site (mfs.com). This information is available at https://www.mfs.com/en-us/what-we-do/announcements.html or at mfs.com/openendfunds by choosing the fund’s name.

INFORMATION ABOUT FUND CONTRACTS AND LEGAL CLAIMS

The fund has entered into contractual arrangements with an investment adviser, administrator, distributor, shareholder servicing agent, 529 program manager (if applicable), and custodian who each provide services to the fund. Unless expressly stated otherwise, shareholders are not parties to, or intended beneficiaries of these contractual arrangements, and these contractual arrangements are not intended to create any shareholder right to enforce them against the service providers or to seek any remedy under them against the service providers, either directly or on behalf of the fund.

Under the Trust’s By-Laws and Declaration of Trust, any claims asserted against or on behalf of the MFS Funds, including claims against Trustees and Officers, must be brought in state and federal courts located within the Commonwealth of Massachusetts.

PROVISION OF FINANCIAL REPORTS AND SUMMARY PROSPECTUSES

The fund produces financial reports every six months and updates its summary prospectus and prospectus annually. To avoid sending duplicate copies of materials to households, only one copy of the fund’s annual and semiannual report and summary prospectus may be mailed to shareholders having the same last name and residential address on the fund’s records. However, any shareholder may contact MFSC (please see back cover for address and telephone number) to request that copies of these reports and summary prospectuses be sent personally to that shareholder.

38

Save paper with eDelivery.

MFS® will send you prospectuses,

reports, and proxies directly via e-mail so you will get information faster with less mailbox clutter.

To sign up:

1. Go to mfs.com.

2. Log in via MFS® Access.

3. Select eDelivery.

If you own your MFS fund shares through a financial institution or a retirement plan, MFS® TALK, MFS® Access, or eDelivery may not be available to you.

CONTACT

WEB SITE

mfs.com

MFS TALK

1-800-637-8255

24 hours a day

ACCOUNT SERVICE AND LITERATURE

Shareholders

1-800-225-2606

Financial advisors

1-800-343-2829

Retirement plan services

1-800-637-1255

MAILING ADDRESS

MFS Service Center, Inc.

P.O. Box 219341

Kansas City, MO 64121-9341

OVERNIGHT MAIL

MFS Service Center, Inc.

Suite 219341

430 W 7th Street

Kansas City, MO 64105-1407

ITEM 2. CODE OF ETHICS.

During the period covered by this report, the Registrant has not amended any provision in its Code of Ethics (the “Code”) that relates to an element of the Code’s definitions enumerated in paragraph (b) of Item 2 of this Form N-CSR. During the period covered by this report, the Registrant did not grant a waiver, including an implicit waiver, from any provision of the Code.

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

Not applicable for semi-annual reports.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

Not applicable for semi-annual reports.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

Not applicable to the Registrant.

ITEM 6. INVESTMENTS

A schedule of investments for Massachusetts Investors Trust is included as part of the report to shareholders under Item 1 of this Form N-CSR.

ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS.

Not applicable to the Registrant.

ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

There were no material changes to the procedures by which shareholders may send recommendations to the Board for nominees to the Registrant’s Board since the Registrant last provided disclosure as to such procedures in response to the requirements of Item 407 (c)(2)(iv) of Regulation S-K or this Item.

ITEM 11. CONTROLS AND PROCEDURES.

(a) Based upon their evaluation of the effectiveness of the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940 (the “Act”)) as conducted within 90 days of the filing date of this report on Form N-CSR, the registrant’s principal financial officer and principal executive officer have concluded that those disclosure controls and procedures provide reasonable assurance that the material information required to be disclosed by the registrant on this report is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms.

(b) There were no changes in the registrant’s internal controls over financial reporting (as defined in Rule 30a-3(d) under the Act) that occurred during the second fiscal quarter of the period covered by the report that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.

ITEM 12. DISCLOSURE OF SECURITIES LENDING ACTIVITIES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 13. EXHIBITS.

(a)    (1) Any code of ethics, or amendment thereto, that is the subject of the disclosure required by Item 2, to the extent that the registrant intends to satisfy the Item 2 requirements through filing of an exhibit: Not applicable.

(2) A separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the Act (17 CFR 270.30a-2): Attached hereto as EX-99.302CERT.

(3) Any written solicitation to purchase securities under Rule 23c-1 under the Act (17 CFR 270.23c-1) sent or given during the period covered by the report by or on behalf of the registrant to 10 or more persons. Not applicable.

(4) Change in the registrant’s independent public accountant. Not applicable.

(b) If the report is filed under Section 13(a) or 15(d) of the Exchange Act, provide the certifications required by Rule 30a-2(b) under the Act (17 CFR 270.30a-2(b)), Rule 13a-14(b) or Rule 15d-14(b) under the Exchange Act (17 CFR 240.13a-14(b) or 240.15d-14(b)) and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350) as an exhibit. A certification furnished pursuant to this paragraph will not be deemed “filed” for the purposes of Section 18 of the Exchange Act (15 U.S.C. 78r), or otherwise subject to the liability of that section. Such certification will not be deemed to be incorporated by reference into any filing under the Securities Act of 1933 or the Exchange Act, except to the extent that the registrant specifically incorporates it by reference. Attached hereto as EX-99.906CERT.

Notice

A copy of the Amended and Restated Declaration of Trust, as amended, of the Registrant is on file with the Secretary of State of The Commonwealth of Massachusetts and notice is hereby given that this instrument is executed on behalf of the Registrant by an officer of the Registrant as an officer and not individually and the obligations of or arising out of this instrument are not binding upon any of the Trustees or shareholders individually, but are binding only upon the assets and property of the respective constituent series of the Registrant.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant) MASSACHUSETTS INVESTORS TRUST

By (Signature and Title)*	DAVID L. DILORENZO
	David L. DiLorenzo, President

Date: August 16, 2019

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)*	DAVID L. DILORENZO
	David L. DiLorenzo, President (Principal Executive Officer)

Date: August 16, 2019

By (Signature and Title)*	JAMES O. YOST
	James O. Yost, Treasurer (Principal Financial Officer and Accounting Officer)

Date: August 16, 2019

* Print name and title of each signing officer under his or her signature.