Oppenheimer Main Street Small Cap Fund NCSRS Certified semi-annual shareholder report (management investment company)

Oppenheimer Main Street Small Cap Fund Inactive N-CSRSCertified semi-annual shareholder report (management investment company)

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 811-22806

Oppenheimer Main Street Small Cap Fund

(Exact name of registrant as specified in charter)

6803 South Tucson Way, Centennial, Colorado 80112-3924

(Address of principal executive offices) (Zip code)

Cynthia Lo Bessette

OFI Global Asset Management, Inc.

225 Liberty Street, New York, New York 10281-1008

(Name and address of agent for service)

Registrant’s telephone number, including area code: (303) 768-3200

Date of fiscal year end: April 30

Date of reporting period: 10/31/2016

Item 1. Reports to Stockholders.

LOGO

Table of Contents



Fund Performance Discussion			3

Top Holdings and Allocations			6

Fund Expenses			9

Statement of Investments			11

Statement of Assets and Liabilities			15

Statement of Operations			17

Statements of Changes in Net Assets			18

Financial Highlights			19

Notes to Financial Statements			24

Board Approval of the Fund’s Investment Advisory and Sub- Advisory Agreements			37

Portfolio Proxy Voting Policies and Guidelines; Updates to Statement of Investments			40

Trustees and Officers			41

Privacy Policy Notice			42

Class A Shares

AVERAGE ANNUAL TOTAL RETURNS AT 10/31/16


	Class A Shares of the Fund
	Without Sales Charge	With Sales Charge	Russell 2000 Index
6-Month	3.73%	-2.24%	6.13%
1-Year	2.92	-3.00	4.11
Since Inception (5/17/13)	7.11	5.29	6.76

Performance data quoted represents past performance, which does not guarantee future results. The investment return and principal value of an investment in the Fund will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Fund returns include changes in share price, reinvested distributions, and a 5.75% maximum applicable sales charge except where “without sales charge” is indicated. Current performance may be lower or higher than the performance quoted. Returns do not consider capital gains or income taxes on an individual’s investment. Returns for periods of less than one year are cumulative and not annualized. For performance data current to the most recent month-end, visit oppenheimerfunds.com or call 1.800.CALL OPP (225.5677). See Fund prospectuses and summary prospectuses for more information on share classes and sales charges.

2 OPPENHEIMER MAIN STREET SMALL CAP FUND

Fund Performance Discussion

The Fund’s Class A shares (without sales charge) returned 3.73% during the reporting period. In comparison, the Russell 2000 Index (the “Index”) returned 6.13% during the same period. The Fund underperformed the Index within the materials, industrials, financials, and health care sectors, due largely to stock selection as well as below-Index exposure to “micro-caps”, which outperformed sharply late in the reporting period. The Fund outperformed the Index within the telecommunication services, energy and utilities sectors primarily as a result of stock selection.

MARKET OVERVIEW

Markets remained turbulent during the reporting period. A large trend for the first half of 2016 was the demand for so called bond proxy stocks with above average dividend yields. This trend was magnified post the Brexit vote as treasury yields, already at historic lows, were under further pressure and future rate hike expectations continued to be pushed farther out. However, the market environment shifted over the third quarter of 2016, when the “risk-on” trade returned. This meant a sharp rebound in lower quality cyclicals, outperformance by smaller versus larger cap stocks, and a rotation away from more stable earnings and defensive-oriented higher dividend companies.

The reporting period saw the market driven by a number of important macroeconomic trends and events:

●

Uncertainty over when or if the Federal Reserve (the “Fed”) would raise interest rates.

●

Continued slow but steady recovery in domestic consumer employment and consumption.

●

Decelerating emerging markets growth, contributing to the weakness in export demand for commodities and other industrial products.

●

Competitive currency devaluations, including negative interest rates in a growing number of jurisdictions, thrusting the world economy into uncharted territory.

●

Impact of Brexit and the increased uncertainty for global markets as a result.

●

The U.S. Presidential elections, and its potential impacts on global trade.

As investors, it is important to know what is and what is not within one’s circle of competence. As such, we strive to keep the portfolio in an all-weather orientation. Whether rates, commodity prices, currencies or even whole economies go up or down, we seek to have a portfolio that is positioned to outperform no matter the environment.

3 OPPENHEIMER MAIN STREET SMALL CAP FUND

Second, we believe we have the skills to identify company management teams that are likely to successfully execute on their plans. Lastly, valuing stocks and seeing what expectations the market is pricing in is also within our skillset. It is not by accident that we weight the portfolio more heavily towards companies that have management teams that are executing (e.g., gaining market share, expanding profit margins), with at least reasonable stock valuations.

FUND REVIEW

Top performing stocks for the Fund this reporting period included MKS Instruments, Inc., Fleetmatics Group PLC, and Endurance Specialty Holdings Ltd. MKS Instruments is a global provider of instruments, subsystems and process control solutions that measure, control, power, monitor and analyze critical parameters of advanced manufacturing processes to improve process performance and productivity. During the reporting period, the company benefited from completing its acquisition of Newport Corporation, a worldwide leader in photonics solutions. MKS Instruments also reported several quarters of strong earnings. Fleetmatics offers software-as-a-service technology (SaaS) through mobile workforce solutions. The company was acquired by Verizon during the summer of 2016 and we exited the position. In October, Japan-based casualty insurer Sompo Holdings announced plans to acquire casualty insurance provider Endurance Specialty Holdings at a significant premium. We exited our position in Endurance as well.

Detractors from performance this period included Sonic Corp., Korn/Ferry International, Prestige Brands Holdings, Inc. Sonic operates and franchises a chain of fast food restaurants. A deceleration in the Quick Service Restaurants (QSR) industry growth rate and stepped up promotional activity negatively impacted the company’s sales trends during the reporting period. The company’s comparisons hence slowed from above an industry growth rate to a sub-industry growth rate during the quarter. Korn/Ferry is an executive staffing and talent management company. The stock detracted from performance after disappointing forward guidance on the company’s fiscal year-end earnings report released in June. Growing economic uncertainty led to a slowdown in the company’s core executive search business, causing a negative earnings revision. Shortly thereafter, the UK Brexit vote led to additional share weakness, as Korn/Ferry does a substantial amount of business in Europe including in Great Britain. As of the reporting period’s end, we maintained our position as we believe the market is pricing in far too pessimistic a view on the company’s business, and therefore, valuation appears to be quite compelling. Prestige Brands sells a variety of over-the-counter healthcare products. Concerns over a decelerating organic growth rate have weighed on the stock. The stock outperformed when organic growth accelerated to mid-single digits, and then retracted when it appeared that its historical low single-digit growth rate is the more sustainable trend line.

4 OPPENHEIMER MAIN STREET SMALL CAP FUND

STRATEGY & OUTLOOK

While bottom-up company research and stock selection continue to be central to our process and strategy, we do have some observations about the current environment. First, the U.S. economy continues its “slow and steady” growth. This is being driven by favorable employment and inflation data while home prices and innovation also continue to help drive the economy higher. However, the potential for protectionist trade policies by the incoming Trump administration could cause global contagion by slowing global trade.

Secondly, U.S. corporate revenues, earnings and free cash flow seem to have topped out for the near term, but earnings growth may resume if tax cuts and stimulative fiscal spending materialize under President Trump. Election results aside, the energy and industrials sectors have shown signs of bottoming. Additionally, while we have previously seen revenue and accounting earnings growth, it has not translated into commensurate cash available for shareholders.

We believe the risks inherent to this market include the misallocation of capital, fueled by an environment of ongoing relatively low interest rates and possibly leading to “bubble-like” valuations for some companies. We intend to maintain our discipline around valuation. Additionally, while innovation is alive and well and continuing to help generate economic growth, fundamental disruptions across market segments have been elevated. We continue to be focused on potential disruption risk to our companies.

Traditionally, during periods of economic uncertainty and heightened market volatility, investors favor stocks of higher quality companies—with greater consistency and stability of revenue and earnings—leading to relatively better stock performance of those companies. We think focusing on companies with economic moats and skilled management teams positions us well, should this environment come to pass. During times of economic volatility such companies frequently widen their lead over weaker competitors. We seek to invest in companies, characterized by these qualities, at compelling valuations and believe this disciplined approach is essential to generating superior long-term performance.

LOGO

Matthew P. Ziehl, CFA and Co-Lead Portfolio Manager, on behalf of the Portfolio Management team: Adam Weiner, Raymond Anello, CFA, Raman Vardharaj, CFA, Joy Budzinski, Kristin Ketner and Magnus Krantz. Mr.Ziehl and Mr. Weiner serve as co-lead Portfolio managers of the Fund

5 OPPENHEIMER MAIN STREET SMALL CAP FUND

Top Holdings and Allocations

TOP TEN COMMON STOCK HOLDINGS


Prestige Brands Holdings, Inc.	2.3	%
Webster Financial Corp.	2.1
MB Financial, Inc.	2.0
MKS Instruments, Inc.	1.9
WellCare Health Plans, Inc.	1.9
CACI International, Inc., Cl. A	1.9
ALLETE, Inc.	1.7
Portland General Electric Co.	1.7
j2 Global, Inc.	1.7
Korn/Ferry International	1.6

Portfolio holdings and allocations are subject to change. Percentages are as of October 31, 2016, and are based on net assets. For more current Fund holdings, please visit oppenheimerfunds. com.

TOP TEN COMMON STOCK INDUSTRIES


Commercial Banks	8.2	%
Real Estate Investment Trusts (REITs)	7.9
Software	6.0
Health Care Providers & Services	5.2
Commercial Services & Supplies	5.2
IT Services	4.7
Hotels, Restaurants & Leisure	4.4
Semiconductors & Semiconductor Equipment	4.1
Specialty Retail	3.6
Electric Utilities	3.5

Portfolio holdings and allocations are subject to change. Percentages are as of October 31, 2016, and are based on net assets.

LOGO

Portfolio holdings and allocations are subject to change. Percentages are as of October 31, 2016, and are based on the total market value of common stocks.

6 OPPENHEIMER MAIN STREET SMALL CAP FUND

Share Class Performance

AVERAGE ANNUAL TOTAL RETURNS WITHOUT SALES CHARGE AS OF 10/31/16


	Inception Date	6-Month			1-Year			Since Inception
Class A (OSCAX)	5/17/13		3.73	%		2.92	%		7.11	%
Class C (OSCCX)	5/17/13		3.38			2.17			6.23
Class I (OSSIX)	5/17/13		3.95			3.42			7.59
Class R (OSCNX)	5/17/13		3.58			2.62			6.76
Class Y (OSCYX)	5/17/13		3.87			3.25			7.49

AVERAGE ANNUAL TOTAL RETURNS WITH SALES CHARGE AS OF 10/31/16


	Inception Date	6-Month			1-Year			Since Inception
Class A (OSCAX)	5/17/13		-2.24	%		-3.00	%		5.29	%
Class C (OSCCX)	5/17/13		2.38			1.17			6.23
Class I (OSSIX)	5/17/13		3.95			3.42			7.59
Class R (OSCNX)	5/17/13		3.58			2.62			6.76
Class Y (OSCYX)	5/17/13		3.87			3.25			7.49

Performance data quoted represents past performance, which does not guarantee future results. The investment return and principal value of an investment in the Fund will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance quoted. Returns do not consider capital gains or income taxes on an individual’s investment. For performance data current to the most recent month-end, visit oppenheimerfunds.com or call 1.800. CALL OPP (225.5677). Fund returns include changes in share price, reinvested distributions, and the applicable sales charge: for Class A shares, the current maximum initial sales charge of 5.75% and for Class C shares, the contingent deferred sales charge (“CDSC”) of 1% for the 1-year period. There is no sales charge for Class I, Class R and Y shares. See Fund prospectuses and summary prospectuses for more information on share classes and sales charges.

The Fund’s performance is compared to the performance of the Russell 2000 Index, which measures the performance of the small-cap segment of the U.S. equity universe. The Index is unmanaged and cannot be purchased directly by investors. While index comparisons may be useful to provide a benchmark for the Fund’s performance, it must be noted that the Fund’s investments are not limited to the investments comprising the Index. Index performance includes reinvestment of income, but does not reflect transaction costs, fees, expenses or taxes. Index performance is shown for illustrative purposes only as a benchmark for the Fund’s performance, and does not predict or depict performance of the Fund. The Fund’s performance reflects the effects of the Fund’s business and operating expenses.

The Fund’s investment strategy and focus can change over time. The mention of specific fund holdings does not constitute a recommendation by OppenheimerFunds, Inc. or its affiliates.

Before investing in any of the Oppenheimer funds, investors should carefully consider a fund’s investment objectives, risks, charges and expenses. Fund

7 OPPENHEIMER MAIN STREET SMALL CAP FUND

prospectuses and summary prospectuses contain this and other information about the funds, and may be obtained by asking your financial advisor, visiting oppenheimerfunds.com, or calling 1.800.CALL OPP (225.5677). Read prospectuses and summary prospectuses carefully before investing.

Shares of Oppenheimer funds are not deposits or obligations of any bank, are not guaranteed by any bank, are not insured by the FDIC or any other agency, and involve investment risks, including the possible loss of the principal amount invested.

8 OPPENHEIMER MAIN STREET SMALL CAP FUND

Fund Expenses

Fund Expenses. As a shareholder of the Fund, you incur two types of costs: (1) transaction costs, which may include sales charges (loads) on purchase payments and/or contingent deferred sales charges on redemptions; and (2) ongoing costs, including management fees; distribution and service fees; and other Fund expenses. These examples are 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 examples are based on an investment of $1,000.00 invested at the beginning of the period and held for the entire 6-month period ended October 31, 2016.

Actual Expenses. The first section of the table provides information about actual account values and actual expenses. You may use the information in this section for the class of shares you hold, together with the amount you invested, to estimate the expense that you paid over the period. Simply divide your account value by $1,000.00 (for example, an $8,600.00 account value divided by $1,000.00 = 8.60), then multiply the result by the number in the first section under the heading entitled “Expenses Paid During 6 Months Ended October 31, 2016” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes. The second section of the table provides information about hypothetical account values and hypothetical expenses based on the Fund’s actual expense ratio for each class of shares, and an assumed rate of return of 5% per year for each class 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 for the class of shares you hold 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 front-end or contingent deferred sales charges (loads). Therefore, the “hypothetical” section of 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.

9 OPPENHEIMER MAIN STREET SMALL CAP FUND


Actual	Beginning Account Value May 1, 2016	Ending Account Value October 31, 2016	Expenses Paid During 6 Months Ended October 31, 2016
Class A	$ 1,000.00	$ 1,037.30	$ 6.34
Class C	1,000.00	1,033.80	10.20
Class I	1,000.00	1,039.50	4.07
Class R	1,000.00	1,035.80	7.62
Class Y	1,000.00	1,038.70	4.64

Hypothetical (5% return before expenses)
Class A	1,000.00	1,019.00	6.28
Class C	1,000.00	1,015.22	10.11
Class I	1,000.00	1,021.22	4.03
Class R	1,000.00	1,017.74	7.55
Class Y	1,000.00	1,020.67	4.59

Expenses are equal to the Fund’s annualized expense ratio for that class, multiplied by the average account value over the period, multiplied by 184/365 (to reflect the one-half year period). Those annualized expense ratios, excluding indirect expenses from affiliated funds, based on the 6-month period ended October 31, 2016 are as follows:


Class	Expense Ratios
Class A		1.23	%
Class C		1.98
Class I		0.79
Class R		1.48
Class Y		0.90

The expense ratios reflect voluntary and/or contractual waivers and/or reimbursements of expenses by the Fund’s Manager. Some of these undertakings may be modified or terminated at any time, as indicated in the Fund’s prospectus. The “Financial Highlights” tables in the Fund’s financial statements, included in this report, also show the gross expense ratios, without such waivers or reimbursements and reduction to custodian expenses, if applicable.

10 OPPENHEIMER MAIN STREET SMALL CAP FUND

STATEMENT OF INVESTMENTS October 31, 2016 Unaudited


	Shares		Value
Common Stocks—97.3%
Consumer Discretionary—10.3%
Auto Components—1.1%
Visteon Corp.		68,247	$	4,818,921

Hotels, Restaurants & Leisure—4.4%
International Speedway Corp., Cl. A		106,484		3,503,324
Popeyes Louisiana Kitchen, Inc.¹		88,036		4,699,362
Sonic Corp.		267,341		6,124,782
Texas Roadhouse, Inc., Cl. A		132,472		5,367,765
				19,695,233

Media—1.2%
Madison Square Garden Co. (The), Cl. A¹		20,172		3,338,264
MDC Partners, Inc., Cl. A		207,149		1,750,409
				5,088,673

Specialty Retail—3.6%
Aaron’s, Inc.		121,514		3,002,611
Burlington Stores, Inc.¹		69,782		5,229,463
Group 1 Automotive, Inc.		95,654		5,765,067
Sally Beauty Holdings, Inc.¹		74,361		1,928,924
				15,926,065

Consumer Staples—3.6%
Beverages—0.7%
Boston Beer Co., Inc. (The), Cl. A¹		20,536		3,188,214

Food Products—1.4%
Pinnacle Foods, Inc.		117,180		6,025,395

Tobacco—1.5%
Universal Corp.		127,074		6,887,411

Energy—3.6%
Energy Equipment & Services—0.4%
RigNet, Inc.¹		126,363		1,895,445

Oil, Gas & Consumable Fuels—3.2%
Cone Midstream Partners LP²		246,108		5,195,340
HollyFrontier Corp.		140,152		3,496,792
Noble Midstream Partners LP^1,2		51,481		1,544,430


	Shares		Value
Oil, Gas & Consumable Fuels (Continued)
Renewable Energy Group, Inc.¹		464,170	$	4,061,488
				14,298,050

Financials—20.3%
Capital Markets—0.8%
Stifel Financial Corp.¹		90,605		3,546,280

Commercial Banks—8.2%
BankUnited, Inc.		190,130		5,540,388
Berkshire Hills Bancorp, Inc.		87,096		2,573,687
Chemical Financial Corp.		79,503		3,414,654
FCB Financial Holdings, Inc., Cl. A¹		64,988		2,424,052
IBERIABANK Corp.		68,269		4,481,860
MB Financial, Inc.		246,075		8,954,669
Webster Financial Corp.		225,145		9,095,858
				36,485,168

Insurance—1.4%
James River Group Holdings Ltd.		140,258		5,279,311
Old Republic International Corp.		49,036		826,747
				6,106,058

Real Estate Investment Trusts (REITs)—7.9%
Brandywine Realty Trust		414,879		6,430,625
Chatham Lodging Trust		211,853		3,749,798
CYS Investments, Inc.		401,054		3,457,086
DiamondRock Hospitality Co.		512,967		4,693,648
DuPont Fabros Technology, Inc.		112,966		4,610,143
Four Corners Property Trust, Inc.		287,868		5,780,389
National Storage Affiliates Trust		249,016		4,875,733
Seritage Growth Properties		27,848		1,268,476
				34,865,898

Real Estate Management & Development—0.5%
Realogy Holdings Corp.		95,193		2,178,968

11 OPPENHEIMER MAIN STREET SMALL CAP FUND

STATEMENT OF INVESTMENTS Unaudited / Continued


	Shares		Value
Thrifts & Mortgage Finance—1.5%
Beneficial Bancorp, Inc.		164,071	$	2,379,030
Oritani Financial Corp.		283,636		4,438,903
				6,817,933

Health Care—13.2%
Biotechnology—1.4%
ACADIA Pharmaceuticals, Inc.¹		68,673		1,600,768
Axovant Sciences Ltd.¹		67,163		826,777
Sage Therapeutics, Inc.¹		36,089		1,571,315
Ultragenyx Pharmaceutical, Inc.¹		34,876		2,057,335
				6,056,195

Health Care Equipment & Supplies—2.5%
NuVasive, Inc.¹		63,932		3,818,658
NxStage Medical, Inc.¹		189,314		4,305,000
Spectranetics Corp. (The)¹		142,488		3,091,990
				11,215,648

Health Care Providers & Services—5.2%
Acadia Healthcare Co., Inc.¹		59,072		2,124,229
Addus HomeCare Corp.¹		47,610		1,204,533
Amedisys, Inc.¹		93,466		4,043,339
Diplomat Pharmacy, Inc.¹		77,958		1,806,287
HealthSouth Corp.		135,899		5,456,345
WellCare Health Plans, Inc.¹		75,030		8,516,655
				23,151,388

Life Sciences Tools & Services—0.8%
VWR Corp.¹		124,146		3,415,256

Pharmaceuticals—3.3%
Akorn, Inc.¹		63,315		1,516,394
Intersect ENT, Inc.¹		128,536		1,876,626
Prestige Brands Holdings, Inc.¹		227,655		10,308,218
TherapeuticsMD, Inc.¹		207,059		1,188,519
				14,889,757


	Shares		Value
Industrials—18.0%
Aerospace & Defense—2.9%
AAR Corp.		92,736	$	2,983,317
Curtiss-Wright Corp.		49,348		4,422,568
Hexcel Corp.		56,400		2,565,636
Wesco Aircraft Holdings, Inc.¹		224,615		2,886,303
				12,857,824

Airlines—1.2%
Spirit Airlines, Inc.¹		110,369		5,289,986

Building Products—1.1%
Masonite International Corp.¹		85,216		4,848,790

Commercial Services & Supplies—5.2%
ABM Industries, Inc.		166,261		6,497,480
ACCO Brands Corp.¹		505,390		5,609,829
Advanced Disposal Services, Inc.¹		115,099		2,305,433
Matthews International Corp., Cl. A		80,834		4,841,956
Pitney Bowes, Inc.		216,914		3,869,746
				23,124,444

Construction & Engineering—2.1%
AECOM¹		94,592		2,634,387
Dycom Industries, Inc.¹		37,499		2,884,798
KBR, Inc.		259,668		3,845,683
				9,364,868

Electrical Equipment—1.0%
Generac Holdings, Inc.¹		117,907		4,491,078

Professional Services—3.2%
Korn/Ferry International		350,813		7,153,077
On Assignment, Inc.¹		204,501		7,036,880
				14,189,957

Road & Rail—1.3%
Genesee & Wyoming, Inc., Cl. A¹		83,485		5,671,971

Information Technology—17.9%
Electronic Equipment, Instruments, & Components—1.4%
SYNNEX Corp.		60,239		6,176,907

12 OPPENHEIMER MAIN STREET SMALL CAP FUND


	Shares		Value
Internet Software & Services—1.7%
j2 Global, Inc.		105,457	$	7,503,265

IT Services—4.7%
Black Knight Financial Services, Inc., Cl. A¹		151,995		5,981,003
Booz Allen Hamilton Holding Corp., Cl. A		209,173		6,373,501
CACI International, Inc., Cl. A¹		85,803		8,395,824
				20,750,328

Semiconductors & Semiconductor Equipment—4.1%
Cavium, Inc.¹		77,456		4,372,391
Cypress Semiconductor Corp.		233,288		2,325,882
MaxLinear, Inc., Cl. A¹		167,730		3,138,228
MKS Instruments, Inc.		169,742		8,563,484
				18,399,985

Software—6.0%
Fortinet, Inc.¹		112,318		3,600,915
Guidewire Software, Inc.¹		74,870		4,301,281
Imperva, Inc.¹		50,838		1,875,922
Paylocity Holding Corp.¹		143,840		6,255,602
Proofpoint, Inc.¹		85,649		6,713,169
Zynga, Inc., Cl. A¹		1,397,369		3,926,607
				26,673,496

Materials—5.6%
Chemicals—0.6%
Ingevity Corp.¹		62,650		2,593,710

Construction Materials—0.6%
Summit Materials, Inc., Cl. A¹		140,520		2,633,345


	Shares		Value
Metals & Mining—1.5%
Kaiser Aluminum Corp.		90,770	$	6,579,917

Paper & Forest Products—2.9%
Boise Cascade Co.¹		191,805		3,692,246
PH Glatfelter Co.		304,114		6,757,413
Schweitzer-Mauduit International, Inc.		68,174		2,516,303
				12,965,962

Utilities—4.8%
Electric Utilities—3.5%
ALLETE, Inc.		125,576		7,696,553
Portland General Electric Co.		176,025		7,681,731
				15,378,284

Gas Utilities—1.3%
Suburban Propane Partners LP²		186,403		6,000,313
Total Common Stocks (Cost $402,281,870)				432,046,386

Investment Company—2.9%
Oppenheimer Institutional Government Money Market Fund, Cl. E, 0.28%^3,4(Cost $12,654,607)		12,654,607		12,654,607
Total Investments,at Value (Cost $414,936,477)		100.2%		444,700,993
Net Other Assets (Liabilities)		(0.2)		(1,038,730	)
Net Assets		100.0%	$	443,662,263

Footnotes to Statement of Investments

1. Non-income producing security.

2. Security is a Master Limited Partnership.

3. Rate shown is the 7-day yield at period end.

13 OPPENHEIMER MAIN STREET SMALL CAP FUND

STATEMENT OF INVESTMENTS Unaudited / Continued

Footnotes to Statement of Investments (Continued)

4. Is or was an affiliate, as defined in the Investment Company Act of 1940, as amended, at or during the reporting period, by virtue of the Fund owning at least 5% of the voting securities of the issuer or as a result of the Fund and the issuer having the same investment adviser. Transactions during the reporting period in which the issuer was an affiliate are as follows:


	Shares April 29, 2016^a		Gross Additions		Gross Reductions		Shares October 31, 2016
Oppenheimer Institutional Government Money Market Fund, Cl. E^b		12,209,334		71,273,759		70,828,486		12,654,607

					Value		Income
Oppenheimer Institutional Government Money Market Fund, Cl. E^b					$	12,654,607	$	23,215

a. Represents the last business day of the Fund’s reporting period.

b. Prior to September 28, 2016, this fund was named Oppenheimer Institutional Money Market Fund.

See accompanying Notes to Financial Statements.

14 OPPENHEIMER MAIN STREET SMALL CAP FUND

STATEMENT OF ASSETS AND LIABILITIES October 31, 2016 Unaudited


Assets
Investments, at value—see accompanying statement of investments:
Unaffiliated companies (cost $402,281,870)	$	432,046,386
Affiliated companies (cost $12,654,607)		12,654,607

		444,700,993
Cash		100,000
Receivables and other assets:
Investments sold		10,345,965
Shares of beneficial interest sold		436,164
Dividends		385,327
Other		25,005

Total assets		455,993,454
Liabilities
Payables and other liabilities:
Investments purchased		11,813,247
Shares of beneficial interest redeemed		466,742
Distribution and service plan fees		18,923
Shareholder communications		6,909
Trustees’ compensation		5,972
Other		19,398

Total liabilities		12,331,191
Net Assets	$	443,662,263


Composition of Net Assets
Par value of shares of beneficial interest	$	35,261
Additional paid-in capital		433,410,026
Accumulated net investment income		1,815,206
Accumulated net realized loss on investments and foreign currency transactions		(21,362,746)
Net unrealized appreciation on investments and translation of assets and liabilities denominated in foreign currencies		29,764,516

Net Assets	$	443,662,263

15 OPPENHEIMER MAIN STREET SMALL CAP FUND

STATEMENT OF ASSETS AND LIABILITIES Unaudited / Continued


Net Asset Value Per Share
Class A Shares:
Net asset value and redemption price per share (based on net assets of $63,585,313 and 5,073,686 shares of beneficial interest outstanding)	$	12.53
Maximum offering price per share (net asset value plus sales charge of 5.75% of offering price)	$	13.29


Class C Shares:
Net asset value, redemption price (excludes applicable contingent deferred sales charge) and offering price per share (based on net assets of $19,561,103 and 1,598,509 shares of beneficial interest outstanding)	$	12.24


Class I Shares:
Net asset value, redemption price and offering price per share (based on net assets of $290,539,610 and 23,028,255 shares of beneficial interest outstanding)	$	12.62


Class R Shares:
Net asset value, redemption price (excludes applicable contingent deferred sales charge) and offering price per share (based on net assets of $5,642,802 and 454,005 shares of beneficial interest outstanding)	$	12.43


Class Y Shares:
Net asset value, redemption price and offering price per share (based on net assets of $64,333,435 and 5,106,122 shares of beneficial interest outstanding)	$	12.60

See accompanying Notes to Financial Statements.

16 OPPENHEIMER MAIN STREET SMALL CAP FUND

STATEMENT OF

OPERATIONS For the Six Months Ended October 31, 2016 Unaudited



Investment Income
Dividends:
Unaffiliated companies (net of foreign withholding taxes of $6,356)	$	3,068,577
Affiliated companies		23,215

Interest		190

Total investment income		3,091,982


Expenses
Management fees		1,625,810

Distribution and service plan fees:
Class A		68,807
Class C		86,099
Class R		12,012

Transfer and shareholder servicing agent fees:
Class A		62,283
Class C		18,954
Class I		45,168
Class R		5,293
Class Y		71,682

Shareholder communications:
Class A		2,546
Class C		848
Class R		173
Class Y		1,384

Trustees’ compensation		11,039

Borrowing fees		3,642

Custodian fees and expenses		1,380

Other		39,547

Total expenses		2,056,667
Less reduction to custodian expenses		(29)
Less waivers and reimbursements of expenses		(30,519)

Net expenses		2,026,119

Net Investment Income		1,065,863

Realized and Unrealized Gain (Loss)
Net realized gain on:
Investments from unaffiliated companies		5,384,800
Foreign currency transactions		1,734

Net realized gain		5,386,534

Net change in unrealized appreciation/depreciation on:
Investments		9,787,070
Translation of assets and liabilities denominated in foreign currencies		(92,413)

Net change in unrealized appreciation/depreciation		9,694,657

Net Increase in Net Assets Resulting from Operations	$	16,147,054


See accompanying Notes to Financial Statements.

17 OPPENHEIMER MAIN STREET SMALL CAP FUND

STATEMENTS OF CHANGES IN NET ASSETS


	Six Months Ended October 31, 2016 (Unaudited)		Year Ended April 29, 2016¹

Operations
Net investment income	$	1,065,863	$	2,898,074

Net realized gain (loss)		5,386,534		(25,020,940)

Net change in unrealized appreciation/depreciation		9,694,657		6,342,145

Net increase (decrease) in net assets resulting from operations		16,147,054		(15,780,721)

Dividends and/or Distributions to Shareholders
Dividends from net investment income:
Class A		—		(135,493)
Class C		—		—
Class I		—		(2,213,988)
Class R		—		(2,189)
Class Y		—		(367,390)

		—		(2,719,060)

Beneficial Interest Transactions
Net increase (decrease) in net assets resulting from beneficial interest transactions:
Class A		12,512,784		18,471,290
Class C		4,747,100		5,263,567
Class I		(15,258,307)		117,733,894
Class R		1,454,002		1,228,864
Class Y		2,534,962		14,953,452

		5,990,541		157,651,067

Net Assets
Total increase		22,137,595		139,151,286

Beginning of period		421,524,668		282,373,382

End of period (including accumulated net investment income of $1,815,206 and $749,343, respectively)	$	443,662,263	$	421,524,668

1. Represents the last business day of the Fund’s reporting period.

See accompanying Notes to Financial Statements.

18 OPPENHEIMER MAIN STREET SMALL CAP FUND

FINANCIAL HIGHLIGHTS


Class A	Six Months Ended October 31, 2016 (Unaudited)		Year Ended April 29, 2016¹		Year Ended April 30, 2015		Period Ended April 30, 2014²

Per Share Operating Data
Net asset value, beginning of period	$	12.08	$	12.76	$	11.57	$	10.00

Income (loss) from investment operations:
Net investment income³		0.01		0.05		0.03		0.06
Net realized and unrealized gain (loss)		0.44		(0.69)		1.20		1.57

Total from investment operations		0.45		(0.64)		1.23		1.63

Dividends and/or distributions to shareholders:
Dividends from net investment income		0.00		(0.04)		(0.00)⁴		(0.02)
Distributions from net realized gain		0.00		0.00		(0.04)		(0.04)

Total dividends and/or distributions to shareholders		0.00		(0.04)		(0.04)		(0.06)

Net asset value, end of period	$	12.53	$	12.08	$	12.76	$	11.57



Total Return, at Net Asset Value⁵		3.73%		(5.06)%		10.67%		16.33%


Ratios/Supplemental Data
Net assets, end of period (in thousands)	$	63,585	$	49,494	$	34,343	$	21,892

Average net assets (in thousands)	$	56,232	$	43,949	$	26,518	$	14,944

Ratios to average net assets:⁶
Net investment income		0.16%		0.44%		0.25%		0.57%
Expenses excluding specific expenses listed below		1.23%		1.25%		1.30%		1.40%
Interest and fees from borrowings		0.00%⁷		0.00%⁷		0.00%		0.00%

Total expenses⁸		1.23%		1.25%		1.30%		1.40%
Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses		1.23%		1.25%		1.25%		1.24%

Portfolio turnover rate		30%		53%		55%		52%

1. Represents the last business day of the Fund’s reporting period.

2. For the period from May 17, 2013 (commencement of operations) to April 30, 2014.

3. Per share amounts calculated based on the average shares outstanding during the period.

4. Less than $0.005 per share.

5. Assumes an initial investment on the business day before the first day of the fiscal period, with all dividends and distributions reinvested in additional shares on the reinvestment date, and redemption at the net asset value calculated on the last business day of the fiscal period. Sales charges are not reflected in the total returns. Total returns are not annualized for periods less than one full year. Returns do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.

6. Annualized for periods less than one full year.

7. Less than 0.005%.

8. Total expenses including indirect expenses from affiliated fund fees and expenses were as follows:

See accompanying Notes to Financial Statements.

19 OPPENHEIMER MAIN STREET SMALL CAP FUND

FINANCIAL HIGHLIGHTS Continued


Class C	Six Months Ended October 31, 2016 (Unaudited)		Year Ended April 29, 2016¹		Year Ended April 30, 2015		Period Ended April 30, 2014²

Per Share Operating Data
Net asset value, beginning of period	$	11.84	$	12.57	$	11.49	$	10.00

Income (loss) from investment operations:
Net investment loss³		(0.04)		(0.04)		(0.07)		(0.04)
Net realized and unrealized gain (loss)		0.44		(0.69)		1.19		1.57

Total from investment operations		0.40		(0.73)		1.12		1.53

Dividends and/or distributions to shareholders:
Dividends from net investment income		0.00		0.00		0.00		0.00
Distributions from net realized gain		0.00		0.00		(0.04)		(0.04)

Total dividends and/or distributions to shareholders		0.00		0.00		(0.04)		(0.04)

Net asset value, end of period	$	12.24	$	11.84	$	12.57	$	11.49



Total Return, at Net Asset Value⁴		3.38%		(5.81)%		9.77%		15.29%


Ratios/Supplemental Data
Net assets, end of period (in thousands)	$	19,561	$	14,441	$	9,878	$	2,252

Average net assets (in thousands)	$	17,116	$	12,117	$	5,461	$	879

Ratios to average net assets:⁵
Net investment loss		(0.60)%		(0.34)%		(0.59)%		(0.34)%
Expenses excluding specific expenses listed below		1.98%		2.01%		2.13%		2.31%
Interest and fees from borrowings		0.00%⁶		0.00%⁶		0.00%		0.00%

Total expenses⁷		1.98%		2.01%		2.13%		2.31%
Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses		1.98%		2.01%		2.13%		2.23%

Portfolio turnover rate		30%		53%		55%		52%

1. Represents the last business day of the Fund’s reporting period.

2. For the period from May 17, 2013 (commencement of operations) to April 30, 2014.

3. Per share amounts calculated based on the average shares outstanding during the period.

4. Assumes an initial investment on the business day before the first day of the fiscal period, with all dividends and distributions reinvested in additional shares on the reinvestment date, and redemption at the net asset value calculated on the last business day of the fiscal period. Sales charges are not reflected in the total returns. Total returns are not annualized for periods less than one full year. Returns do not reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.

5. Annualized for periods less than one full year.

6. Less than 0.005%.

7. Total expenses including indirect expenses from affiliated fund fees and expenses were as follows:

See accompanying Notes to Financial Statements.

20 OPPENHEIMER MAIN STREET SMALL CAP FUND


Class I	Six Months Ended October 31, 2016 (Unaudited)		Year Ended April 29, 2016¹		Year Ended April 30, 2015		Period Ended April 30, 2014²

Per Share Operating Data
Net asset value, beginning of period	$	12.14	$	12.82	$	11.58	$	10.00

Income (loss) from investment operations:
Net investment income³		0.04		0.11		0.10		0.09
Net realized and unrealized gain (loss)		0.44		(0.70)		1.20		1.58

Total from investment operations		0.48		(0.59)		1.30		1.67

Dividends and/or distributions to shareholders:
Dividends from net investment income		0.00		(0.09)		(0.02)		(0.05)
Distributions from net realized gain		0.00		0.00		(0.04)		(0.04)

Total dividends and/or distributions to shareholders		0.00		(0.09)		(0.06)		(0.09)

Net asset value, end of period	$	12.62	$	12.14	$	12.82	$	11.58



Total Return, at Net Asset Value⁴		3.95%		(4.63)%		11.26%		16.73%


Ratios/Supplemental Data
Net assets, end of period (in thousands)	$	290,540	$	294,108	$	187,997	$	12

Average net assets (in thousands)	$	298,508	$	256,727	$	95,238	$	12

Ratios to average net assets:⁵
Net investment income		0.61%		0.91%		0.80%		0.86%
Expenses excluding specific expenses listed below		0.79%		0.80%		0.80%		1.09%
Interest and fees from borrowings		0.00%⁶		0.00%⁶		0.00%		0.00%

Total expenses⁷		0.79%		0.80%		0.80%		1.09%
Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses		0.79%		0.80%		0.79%		0.80%

Portfolio turnover rate		30%		53%		55%		52%

1. Represents the last business day of the Fund’s reporting period.

2. For the period from May 17, 2013 (commencement of operations) to April 30, 2014.

3. Per share amounts calculated based on the average shares outstanding during the period.

5. Annualized for periods less than one full year.

6. Less than 0.005%.

7. Total expenses including indirect expenses from affiliated fund fees and expenses were as follows:

See accompanying Notes to Financial Statements.

21 OPPENHEIMER MAIN STREET SMALL CAP FUND

FINANCIAL HIGHLIGHTS Continued


Class R	Six Months Ended October 31, 2016 (Unaudited)		Year Ended April 29, 2016¹		Year Ended April 30, 2015		Period Ended April 30, 2014²

Per Share Operating Data
Net asset value, beginning of period	$	12.00	$	12.68	$	11.53	$	10.00

Income (loss) from investment operations:
Net investment income (loss)³		(0.01)		0.02		(0.01)		0.02
Net realized and unrealized gain (loss)		0.44		(0.69)		1.20		1.56

Total from investment operations		0.43		(0.67)		1.19		1.58

Dividends and/or distributions to shareholders:
Dividends from net investment income		0.00		(0.01)		0.00		(0.01)
Distributions from net realized gain		0.00		0.00		(0.04)		(0.04)

Total dividends and/or distributions to shareholders		0.00		(0.01)		(0.04)		(0.05)

Net asset value, end of period	$	12.43	$	12.00	$	12.68	$	11.53



Total Return, at Net Asset Value⁴		3.58%		(5.31)%		10.34%		15.82%


Ratios/Supplemental Data
Net assets, end of period (in thousands)	$	5,643	$	4,060	$	3,027	$	650

Average net assets (in thousands)	$	4,781	$	3,544	$	1,403	$	271

Ratios to average net assets:⁵
Net investment income (loss)		(0.09)%		0.15%		(0.09)%		0.19%
Expenses excluding specific expenses listed below		1.48%		1.51%		1.61%		1.76%
Interest and fees from borrowings		0.00%⁶		0.00%⁶		0.00%		0.00%

Total expenses⁷		1.48%		1.51%		1.61%		1.76%
Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses		1.48%		1.51%		1.60%		1.71%

Portfolio turnover rate		30%		53%		55%		52%

1. Represents the last business day of the Fund’s reporting period.

2. For the period from May 17, 2013 (commencement of operations) to April 30, 2014.

3. Per share amounts calculated based on the average shares outstanding during the period.

5. Annualized for periods less than one full year.

6. Less than 0.005%.

7. Total expenses including indirect expenses from affiliated fund fees and expenses were as follows:

See accompanying Notes to Financial Statements.

22 OPPENHEIMER MAIN STREET SMALL CAP FUND


Class Y	Six Months Ended October 31, 2016 (Unaudited)		Year Ended April 29, 2016¹		Year Ended April 30, 2015		Period Ended April 30, 2014²

Per Share Operating Data
Net asset value, beginning of period	$	12.13	$	12.81	$	11.59	$	10.00

Income (loss) from investment operations:
Net investment income³		0.03		0.09		0.04		0.09
Net realized and unrealized gain (loss)		0.44		(0.69)		1.24		1.58

Total from investment operations		0.47		(0.60)		1.28		1.67

Dividends and/or distributions to shareholders:
Dividends from net investment income		0.00		(0.08)		(0.02)		(0.04)
Distributions from net realized gain		0.00		0.00		(0.04)		(0.04)

Total dividends and/or distributions to shareholders		0.00		(0.08)		(0.06)		(0.08)

Net asset value, end of period	$	12.60	$	12.13	$	12.81	$	11.59



Total Return, at Net Asset Value⁴		3.87%		(4.72)%		11.05%		16.76%


Ratios/Supplemental Data
Net assets, end of period (in thousands)	$	64,333	$	59,422	$	47,128	$	432

Average net assets (in thousands)	$	64,638	$	54,043	$	6,437	$	358

Ratios to average net assets:⁵
Net investment income		0.49%		0.76%		0.33%		0.89%
Expenses excluding specific expenses listed below		0.98%		1.00%		1.01%		1.33%
Interest and fees from borrowings		0.00%⁶		0.00%⁶		0.00%		0.00%

Total expenses⁷		0.98%		1.00%		1.01%		1.33%
Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses		0.90%		0.90%		0.88%		0.90%

Portfolio turnover rate		30%		53%		55%		52%

1. Represents the last business day of the Fund’s reporting period.

2. For the period from May 17, 2013 (commencement of operations) to April 30, 2014.

3. Per share amounts calculated based on the average shares outstanding during the period.

5. Annualized for periods less than one full year.

6. Less than 0.005%.

7. Total expenses including indirect expenses from affiliated fund fees and expenses were as follows:

See accompanying Notes to Financial Statements.

23 OPPENHEIMER MAIN STREET SMALL CAP FUND

NOTES TO FINANCIAL STATEMENTS October 31, 2016 Unaudited

1. Organization

Oppenheimer Main Street Small Cap Fund (the “Fund”) is registered under the Investment Company Act of 1940 (“1940 Act”), as amended, as a diversified open-end management investment company. The Fund’s investment objective is to seek capital appreciation. The Fund’s investment adviser is OFI Global Asset Management, Inc. (“OFI Global” or the “Manager”), a wholly-owned subsidiary of OppenheimerFunds, Inc. (“OFI” or the “Sub-Adviser”). The Manager has entered into a sub-advisory agreement with OFI.

The Fund offers Class A, Class C, Class I, Class R and Class Y shares. As of July 1, 2014, Class N shares were renamed Class R shares. Class N shares subject to a contingent deferred sales charge (“CDSC”) on July 1, 2014, continue to be subject to a CDSC after the shares were renamed. Purchases of Class R shares occurring on or after July 1, 2014, are not subject to a CDSC upon redemption. Class A shares are sold at their offering price, which is normally net asset value plus a front-end sales charge. Class C and Class R shares are sold without a front-end sales charge but may be subject to a CDSC. Class R shares are sold only through retirement plans. Retirement plans that offer Class R shares may impose charges on those accounts. Class I and Class Y shares are sold to certain institutional investors or intermediaries without either a front-end sales charge or a CDSC, however, the intermediaries may impose charges on their accountholders who beneficially own Class I and Class Y shares. All classes of shares have identical rights and voting privileges with respect to the Fund in general and exclusive voting rights on matters that affect that class alone. Earnings, net assets and net asset value per share may differ due to each class having its own expenses, such as transfer and shareholder servicing agent fees and shareholder communications, directly attributable to that class. Class A, C and R shares have separate distribution and/or service plans under which they pay fees. Class I and Class Y shares do not pay such fees.

The following is a summary of significant accounting policies followed in the Fund’s preparation of financial statements in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”).

2. Significant Accounting Policies

Security Valuation. All investments in securities are recorded at their estimated fair value, as described in Note 3.

Foreign Currency Translation. The Fund’s accounting records are maintained in U.S. dollars. The values of securities denominated in foreign currencies and amounts related to the purchase and sale of foreign securities and foreign investment income are translated into U.S. dollars as of the close of the New York Stock Exchange (the “Exchange”), normally 4:00 P.M. Eastern time, on each day the Exchange is open for trading. Foreign exchange rates may be valued primarily using a reliable bank, dealer or service authorized by the Board of Trustees.

Reported net realized gains and losses from foreign currency transactions arise from sales of portfolio securities, sales and maturities of short-term securities, sales of foreign currencies, exchange rate fluctuations between the trade and settlement dates on securities transactions, and the difference between the amounts of dividends, interest, and foreign withholding

24 OPPENHEIMER MAIN STREET SMALL CAP FUND

2. Significant Accounting Policies (Continued)

taxes recorded on the Fund’s books and the U.S. dollar equivalent of the amounts actually received or paid. Net unrealized appreciation and depreciation on the translation of assets and liabilities denominated in foreign currencies arise from changes in the values of assets and liabilities, including investments in securities at fiscal period end, resulting from changes in exchange rates.

The effect of changes in foreign currency exchange rates on investments is separately identified from the fluctuations arising from changes in market values of securities held and reported with all other foreign currency gains and losses in the Fund’s Statement of Operations.

Allocation of Income, Expenses, Gains and Losses. Income, expenses (other than those attributable to a specific class), gains and losses are allocated on a daily basis to each class of shares based upon the relative proportion of net assets represented by such class. Operating expenses directly attributable to a specific class are charged against the operations of that class.

Dividends and Distributions to Shareholders. Dividends and distributions to shareholders, which are determined in accordance with income tax regulations and may differ from U.S. GAAP, are recorded on the ex-dividend date. Income and capital gain distributions, if any, are declared and paid annually or at other times as deemed necessary by the Manager.

The tax character of distributions is determined as of the Fund’s fiscal year end. Therefore, a portion of the Fund’s distributions made to shareholders prior to the Fund’s fiscal year end may ultimately be categorized as a tax return of capital.

Investment Income. Dividend income is recorded on the ex-dividend date or upon ex-dividend notification in the case of certain foreign dividends where the ex-dividend date may have passed. Non-cash dividends included in dividend income, if any, are recorded at the fair market value of the securities received. Interest income is recognized on an accrual basis. Discount and premium, which are included in interest income on the Statement of Operations, are amortized or accreted daily.

Return of Capital Estimates. Distributions received from the Fund’s investments in Master Limited Partnerships (MLPs) and Real Estate Investments Trusts (REITs), generally are comprised of income and return of capital. The Fund records investment income and return of capital based on estimates. Such estimates are based on historical information available from each MLP, REIT and other industry sources. These estimates may subsequently be revised based on information received from MLPs and REITs after their tax reporting periods are concluded.

Custodian Fees. “Custodian fees and expenses” in the Statement of Operations may include interest expense incurred by the Fund on any cash overdrafts of its custodian account during the period. Such cash overdrafts may result from the effects of failed trades in portfolio

25 OPPENHEIMER MAIN STREET SMALL CAP FUND

NOTES TO FINANCIAL STATEMENTS Unaudited / Continued

2. Significant Accounting Policies (Continued)

securities and from cash outflows resulting from unanticipated shareholder redemption activity. The Fund pays interest to its custodian on such cash overdrafts, to the extent they are not offset by positive cash balances maintained by the Fund, at a rate equal to the Federal Funds Rate plus 0.50%. The “Reduction to custodian expenses” line item, if applicable, represents earnings on cash balances maintained by the Fund during the period. Such interest expense and other custodian fees may be paid with these earnings.

Security Transactions. Security transactions are recorded on the trade date. Realized gains and losses on securities sold are determined on the basis of identified cost.

Indemnifications. The Fund’s organizational documents provide current and former Trustees and officers with a limited indemnification against liabilities arising in connection with the performance of their duties to the Fund. In the normal course of business, the Fund may also enter into contracts that provide general indemnifications. The Fund’s maximum exposure under these arrangements is unknown as this would be dependent on future claims that may be made against the Fund. The risk of material loss from such claims is considered remote.

Federal Taxes. The Fund intends to comply with provisions of the Internal Revenue Code applicable to regulated investment companies and to distribute substantially all of its investment company taxable income to shareholders. Therefore, no federal income or excise tax provision is required. The Fund files income tax returns in U.S. federal and applicable state jurisdictions. The statute of limitations on the Fund’s tax return filings generally remains open for the three preceding fiscal reporting period ends. The Fund has analyzed its tax positions for the fiscal year ended April 29, 2016, including open tax years, and does not believe there are any uncertain tax positions requiring recognition in the Fund’s financial statements.

During the fiscal year ended April 29, 2016, the Fund did not utilize any capital loss carryforward to offset capital gains realized in that fiscal year. Details of the fiscal year ended April 29, 2016 capital loss carryforwards are included in the table below. Capital loss carryforwards with no expiration, if any, must be utilized prior to those with expiration dates. Capital losses with no expiration will be carried forward to future years if not offset by gains.


Expiring
No expiration	$	25,450,099

At period end, it is estimated that the capital loss carryforwards would be $20,063,565 which will not expire. The estimated capital loss carryforward represents the carryforward as of the end of the last fiscal year, increased or decreased by capital losses or gains realized in the first six months of the current fiscal year. During the reporting period, it is estimated that the Fund will utilize $5,386,534 of capital loss carryforward to offset realized capital gains.

Net investment income (loss) and net realized gain (loss) may differ for financial statement and tax purposes. The character of dividends and distributions made during the fiscal year from net investment income or net realized gains are determined in accordance with federal

26 OPPENHEIMER MAIN STREET SMALL CAP FUND

2. Significant Accounting Policies (Continued)

income tax requirements, which may differ from the character of net investment income or net realized gains presented in those financial statements in accordance with U.S. GAAP. Also, due to timing of dividends and distributions, the fiscal year in which amounts are distributed may differ from the fiscal year in which the income or net realized gain was recorded by the Fund.

The aggregate cost of securities and other investments and the composition of unrealized appreciation and depreciation of securities and other investments for federal income tax purposes at period end are noted in the following table. The primary difference between book and tax appreciation or depreciation of securities and other investments, if applicable, is attributable to the tax deferral of losses or tax realization of financial statement unrealized gain or loss.


Federal tax cost of securities	$	414,936,477

Gross unrealized appreciation	$	50,008,458
Gross unrealized depreciation		(20,243,942)

Net unrealized appreciation	$	29,764,516

Use of Estimates. The preparation of financial statements in conformity with U.S. GAAP 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.

3. Securities Valuation

The Fund calculates the net asset value of its shares as of 4:00 P.M. Eastern time, on each day the New York Stock Exchange (the “Exchange”) is open for trading, except in the case of a scheduled early closing of the Exchange, in which case the Fund will calculate net asset value of the shares as of the scheduled early closing time of the Exchange.

The Fund’s Board has adopted procedures for the valuation of the Fund’s securities and has delegated the day-to-day responsibility for valuation determinations under those procedures to the Manager. The Manager has established a Valuation Committee which is responsible for determining a “fair valuation” for any security for which market quotations are not “readily available.” The Valuation Committee’s fair valuation determinations are subject to review, approval and ratification by the Fund’s Board at its next regularly scheduled meeting covering the calendar quarter in which the fair valuation was determined.

Valuation Methods and Inputs

Securities are valued using unadjusted quoted market prices, when available, as supplied primarily by third party pricing services or dealers.

The following methodologies are used to determine the market value or the fair value of the types of securities described below:

Securities traded on a registered U.S. securities exchange (including exchange-traded derivatives other than futures and futures options) are valued based on the last sale price

27 OPPENHEIMER MAIN STREET SMALL CAP FUND

NOTES TO FINANCIAL STATEMENTS Unaudited / Continued

3. Securities Valuation (Continued)

of the security reported on the principal exchange on which it is traded, prior to the time when the Fund’s assets are valued. In the absence of a sale, the security is valued at the mean between the bid and asked price on the principal exchange or, if not available from the principal exchange, obtained from two dealers. If bid and asked prices are not available from either the exchange or two dealers, the security is valued by using one of the following methodologies (listed in order of priority): (1) a bid from the principal exchange, (2) the mean between the bid and asked price as provided by a single dealer, or (3) a bid from a single dealer. A security of a foreign issuer traded on a foreign exchange, but not listed on a registered U.S. securities exchange, is valued based on the last sale price on the principal exchange on which the security is traded, as identified by the third party pricing service used by the Manager, prior to the time when the Fund’s assets are valued. If the last sale price is unavailable, the security is valued at the most recent official closing price on the principal exchange on which it is traded. If the last sales price or official closing price for a foreign security is not available, the security is valued at the mean between the bid and asked price per the exchange or, if not available from the exchange, obtained from two dealers. If bid and asked prices are not available from either the exchange or two dealers, the security is valued by using one of the following methodologies (listed in order of priority): (1) a bid from the exchange, (2) the mean between the bid and asked price as provided by a single dealer, or (3) a bid from a single dealer.

Shares of a registered investment company that are not traded on an exchange are valued at that investment company’s net asset value per share.

Corporate and government debt securities (of U.S. or foreign issuers) and municipal debt securities, event-linked bonds, loans, mortgage-backed securities, collateralized mortgage obligations, and asset-backed securities are valued at the mean between the “bid” and “asked” prices utilizing evaluated prices obtained from third party pricing services or broker-dealers who may use matrix pricing methods to determine the evaluated prices.

Short-term money market type debt securities with a remaining maturity of sixty days or less are valued at cost adjusted by the amortization of discount or premium to maturity (amortized cost), which approximates market value. Short-term debt securities with a remaining maturity in excess of sixty days are valued at the mean between the “bid” and “asked” prices utilizing evaluated prices obtained from third party pricing services or broker-dealers.

A description of the standard inputs that may generally be considered by the third party pricing vendors in determining their evaluated prices is provided below.


Security Type		Standard inputs generally considered by third-party pricing vendors
Corporate debt, government debt, municipal, mortgage- backed and asset-backed securities		Reported trade data, broker-dealer price quotations, benchmark yields, issuer spreads on comparable securities, the credit quality, yield, maturity, and other appropriate factors.
Loans		Information obtained from market participants regarding reported trade data and broker-dealer price quotations.
Event-linked bonds		Information obtained from market participants regarding reported trade data and broker-dealer price quotations.

28 OPPENHEIMER MAIN STREET SMALL CAP FUND

3. Securities Valuation (Continued)

If a market value or price cannot be determined for a security using the methodologies described above, or if, in the “good faith” opinion of the Manager, the market value or price obtained does not constitute a “readily available market quotation,” or a significant event has occurred that would materially affect the value of the security, the security is fair valued either (i) by a standardized fair valuation methodology applicable to the security type or the significant event as previously approved by the Valuation Committee and the Fund’s Board or (ii) as determined in good faith by the Manager’s Valuation Committee. The Valuation Committee considers all relevant facts that are reasonably available, through either public information or information available to the Manager, when determining the fair value of a security. Fair value determinations by the Manager are subject to review, approval and ratification by the Fund’s Board at its next regularly scheduled meeting covering the calendar quarter in which the fair valuation was determined. Those fair valuation standardized methodologies include, but are not limited to, valuing securities at the last sale price or initially at cost and subsequently adjusting the value based on: changes in company specific fundamentals, changes in an appropriate securities index, or changes in the value of similar securities which may be further adjusted for any discounts related to security-specific resale restrictions. When possible, such methodologies use observable market inputs such as unadjusted quoted prices of similar securities, observable interest rates, currency rates and yield curves. The methodologies used for valuing securities are not necessarily an indication of the risks associated with investing in those securities nor can it be assured that the Fund can obtain the fair value assigned to a security if it were to sell the security.

To assess the continuing appropriateness of security valuations, the Manager, or its third party service provider who is subject to oversight by the Manager, regularly compares prior day prices, prices on comparable securities, and sale prices to the current day prices and challenges those prices exceeding certain tolerance levels with the third party pricing service or broker source. For those securities valued by fair valuations, whether through a standardized fair valuation methodology or a fair valuation determination, the Valuation Committee reviews and affirms the reasonableness of the valuations based on such methodologies and fair valuation determinations on a regular basis after considering all relevant information that is reasonably available.

Classifications

Each investment asset or liability of the Fund is assigned a level at measurement date based on the significance and source of the inputs to its valuation. Various data inputs are used in determining the value of each of the Fund’s investments as of the reporting period end. These data inputs are categorized in the following hierarchy under applicable financial accounting standards:

1) Level 1-unadjusted quoted prices in active markets for identical assets or liabilities (including securities actively traded on a securities exchange)

2) Level 2-inputs other than unadjusted quoted prices that are observable for the asset or liability (such as unadjusted quoted prices for similar assets and market corroborated inputs

29 OPPENHEIMER MAIN STREET SMALL CAP FUND

NOTES TO FINANCIAL STATEMENTS Unaudited / Continued

3. Securities Valuation (Continued)

such as interest rates, prepayment speeds, credit risks, etc.)

3) Level 3-significant unobservable inputs (including the Manager’s own judgments about assumptions that market participants would use in pricing the asset or liability).

The inputs used for valuing securities are not necessarily an indication of the risks associated with investing in those securities.

The Fund classifies each of its investments in investment companies which are publicly offered as Level 1. Investment companies that are not publicly offered are measured using net asset value as a practical expedient, and are not classified in the fair value hierarchy.

The table below categorizes amounts that are included in the Fund’s Statement of Assets and Liabilities at period end based on valuation input level:


	Level 1— Unadjusted Quoted Prices		Level 2— Other Significant Observable Inputs		Level 3— Significant Unobservable Inputs		Value
Assets Table
Investments, at Value:
Common Stocks
Consumer Discretionary	$	45,528,892	$	—	$	—	$	45,528,892
Consumer Staples		16,101,020		—		—		16,101,020
Energy		16,193,495		—		—		16,193,495
Financials		90,000,305		—		—		90,000,305
Health Care		58,728,244		—		—		58,728,244
Industrials		79,838,918		—		—		79,838,918
Information Technology		79,503,981		—		—		79,503,981
Materials		24,772,934		—		—		24,772,934
Utilities		21,378,597		—		—		21,378,597
Investment Company		12,654,607		—		—		12,654,607

Total Assets	$	444,700,993	$	—	$	—	$	444,700,993

Forward currency exchange contracts and futures contracts, if any, are reported at their unrealized appreciation/depreciation at measurement date, which represents the change in the contract’s value from trade date. All additional assets and liabilities included in the above table are reported at their market value at measurement date.

4. Investments and Risks

Investments in Affiliated Funds. The Fund is permitted to invest in other mutual funds advised by the Manager (“Affiliated Funds”). Affiliated Funds are open-end management investment companies registered under the 1940 Act, as amended. The Manager is the investment adviser of, and the Sub-Adviser provides investment and related advisory services to, the Affiliated Funds. When applicable, the Fund’s investments in Affiliated Funds are included in the Statement of Investments. Shares of Affiliated Funds are valued at their net asset value per share. As a shareholder, the Fund is subject to its proportional share of the Affiliated Funds’ expenses, including their management fee. The Manager will waive fees and/

30 OPPENHEIMER MAIN STREET SMALL CAP FUND

4. Investments and Risks (Continued)

or reimburse Fund expenses in an amount equal to the indirect management fees incurred through the Fund’s investment in the Affiliated Funds.

Each of the Affiliated Funds in which the Fund invests has its own investment risks, and those risks can affect the value of the Fund’s investments and therefore the value of the Fund’s shares. To the extent that the Fund invests more of its assets in one Affiliated Fund than in another, the Fund will have greater exposure to the risks of that Affiliated Fund.

Investments in Money Market Instruments. The Fund is permitted to invest its free cash balances in money market instruments to provide liquidity or for defensive purposes. The Fund may invest in money market instruments by investing in Class E shares of Oppenheimer Institutional Government Money Market Fund (“IGMMF”), formerly known as Oppenheimer Institutional Money Market Fund, which is an Affiliated Fund. IGMMF is regulated as a money market fund under the 1940 Act, as amended. The Fund may also invest in money market instruments directly or in other affiliated or unaffiliated money market funds.

Master Limited Partnerships (“MLPs”). MLPs issue common units that represent an equity ownership interest in a partnership and provide limited voting rights. MLP common units are registered with the Securities and Exchange Commission (“SEC”), and are freely tradable on securities exchanges such as the NYSE and the NASDAQ Stock Market (“NASDAQ”), or in the over-the-counter (“OTC”) market. An MLP consists of one or more general partners, who conduct the business, and one or more limited partners, who contribute capital. MLP common unit holders have a limited role in the partnership’s operations and management. The Fund, as a limited partner, normally would not be liable for the debts of the MLP beyond the amounts the Fund has contributed, but would not be shielded to the same extent that a shareholder of a corporation would be. In certain circumstances creditors of an MLP would have the right to seek return of capital distributed to a limited partner. This right of an MLP’s creditors would continue after the Fund sold its investment in the MLP.

Equity Security Risk. Stocks and other equity securities fluctuate in price. The value of the Fund’s portfolio may be affected by changes in the equity markets generally. Equity markets may experience significant short-term volatility and may fall sharply at times. Different markets may behave differently from each other and U.S. equity markets may move in the opposite direction from one or more foreign stock markets. Adverse events in any part of the equity or fixed-income markets may have unexpected negative effects on other market segments.

The prices of individual equity securities generally do not all move in the same direction at the same time and a variety of factors can affect the price of a particular company’s securities. These factors may include, but are not limited to, poor earnings reports, a loss of customers, litigation against the company, general unfavorable performance of the company’s sector or industry, or changes in government regulations affecting the company or its industry.

Shareholder Concentration. At period end, two shareholders each owned 20% or more of the Fund’s total outstanding shares.

31 OPPENHEIMER MAIN STREET SMALL CAP FUND

NOTES TO FINANCIAL STATEMENTS Unaudited / Continued

4. Investments and Risks (Continued)

The shareholders are related parties of the Fund. Related parties may include, but are not limited to, the investment manager and its affiliates, affiliated broker dealers, fund of funds, and directors or employees. Related parties owned 63% of the Fund’s total outstanding shares at period end.

5. Market Risk Factors

The Fund’s investments in securities and/or financial derivatives may expose the Fund to various market risk factors:

Commodity Risk. Commodity risk relates to the change in value of commodities or commodity indexes as they relate to increases or decreases in the commodities market. Commodities are physical assets that have tangible properties. Examples of these types of assets are crude oil, heating oil, metals, livestock, and agricultural products.

Credit Risk. Credit risk relates to the ability of the issuer of debt to meet interest and principal payments, or both, as they come due. In general, lower-grade, higher-yield debt securities are subject to credit risk to a greater extent than lower-yield, higher-quality securities.

Equity Risk. Equity risk relates to the change in value of equity securities as they relate to increases or decreases in the general market.

Foreign Exchange Rate Risk. Foreign exchange rate risk relates to the change in the U.S. dollar value of a security held that is denominated in a foreign currency. The U.S. dollar value of a foreign currency denominated security will decrease as the dollar appreciates against the currency, while the U.S. dollar value will increase as the dollar depreciates against the currency.

Interest Rate Risk. Interest rate risk refers to the fluctuations in value of fixed-income securities resulting from the inverse relationship between price and yield. For example, an increase in general interest rates will tend to reduce the market value of already issued fixed-income investments, and a decline in general interest rates will tend to increase their value. In addition, debt securities with longer maturities, which tend to have higher yields, are subject to potentially greater fluctuations in value from changes in interest rates than obligations with shorter maturities.

Volatility Risk. Volatility risk refers to the magnitude of the movement, but not the direction of the movement, in a financial instrument’s price over a defined time period. Large increases or decreases in a financial instrument’s price over a relative time period typically indicate greater volatility risk, while small increases or decreases in its price typically indicate lower volatility risk.

6. Shares of Beneficial Interest

The Fund has authorized an unlimited number of $0.001 par value shares of beneficial interest of each class. Transactions in shares of beneficial interest were as follows:

32 OPPENHEIMER MAIN STREET SMALL CAP FUND

6. Shares of Beneficial Interest (Continued)


	Six Months Ended October 31, 2016						Year Ended April 29, 2016¹
	Shares			Amount			Shares			Amount

Class A
Sold		1,683,937		$	21,387,475			3,133,948		$	38,354,256
Dividends and/or distributions reinvested		—			—			10,627			133,978
Redeemed		(706,365	)		(8,874,691	)		(1,738,889	)		(20,016,944	)

Net increase		977,572		$	12,512,784			1,405,686		$	18,471,290



Class C
Sold		540,172		$	6,733,831			633,134		$	7,582,742
Dividends and/or distributions reinvested		—			—			—			—
Redeemed		(160,955	)		(1,986,731	)		(199,634	)		(2,319,175	)

Net increase		379,217		$	4,747,100			433,500		$	5,263,567



Class I
Sold		824,852		$	10,442,931			17,020,185		$	208,714,134
Dividends and/or distributions reinvested		—			—			175,055			2,213,898
Redeemed		(2,028,006	)		(25,701,238	)		(7,631,606	)		(93,194,138	)

Net increase (decrease)		(1,203,154	)	$	(15,258,307	)		9,563,634		$	117,733,894



Class R
Sold		159,172		$	1,995,567			199,157		$	2,408,288
Dividends and/or distributions reinvested		—			—			174			2,181
Redeemed		(43,588	)		(541,565	)		(99,675	)		(1,181,605	)

Net increase		115,584		$	1,454,002			99,656		$	1,228,864



Class Y
Sold		1,231,111		$	15,408,691			2,871,766		$	35,020,262
Dividends and/or distributions reinvested		—			—			29,060			367,311
Redeemed		(1,024,556	)		(12,873,729	)		(1,680,066	)		(20,434,121	)

Net increase		206,555		$	2,534,962			1,220,760		$	14,953,452

1. Represents the last business day of the Fund’s reporting period.

7. Purchases and Sales of Securities

The aggregate cost of purchases and proceeds from sales of securities, other than short-term obligations and investments in IGMMF, for the reporting period were as follows:


	Purchases		Sales

Investment securities	$	134,097,406	$	127,839,771

8. Fees and Other Transactions with Affiliates

Management Fees. Under the investment advisory agreement, the Fund pays the Manager a management fee based on the daily net assets of the Fund at an annual rate as shown in the following table:

33 OPPENHEIMER MAIN STREET SMALL CAP FUND

NOTES TO FINANCIAL STATEMENTS Unaudited / Continued

8. Fees and Other Transactions with Affiliates (Continued)


Fee Schedule

Up to $200 million			0.75%
Next $200 million			0.72
Next $200 million			0.69
Next $200 million			0.66
Next $4.2 billion			0.60
Over $5 billion			0.58

The Fund’s effective management fee for the reporting period was 0.73% of average annual net assets before any applicable waivers.

Sub-Adviser Fees. The Manager has retained the Sub-Adviser to provide the day-to-day portfolio management of the Fund. Under the Sub-Advisory Agreement, the Manager pays the Sub-Adviser an annual fee in monthly installments, equal to a percentage of the investment management fee collected by the Manager from the Fund, which shall be calculated after any investment management fee waivers. The fee paid to the Sub-Adviser is paid by the Manager, not by the Fund.

Transfer Agent Fees. OFI Global (the “Transfer Agent”) serves as the transfer and shareholder servicing agent for the Fund. The Fund pays the Transfer Agent a fee based on annual net assets. Fees incurred and average net assets for each class with respect to these services are detailed in the Statement of Operations and Financial Highlights, respectively.

Sub-Transfer Agent Fees. The Transfer Agent has retained Shareholder Services, Inc., a wholly-owned subsidiary of OFI (the “Sub-Transfer Agent”), to provide the day-to-day transfer agent and shareholder servicing of the Fund. Under the Sub-Transfer Agency Agreement, the Transfer Agent pays the Sub-Transfer Agent an annual fee in monthly installments, equal to a percentage of the transfer agent fee collected by the Transfer Agent from the Fund, which shall be calculated after any applicable fee waivers. The fee paid to the Sub-Transfer Agent is paid by the Transfer Agent, not by the Fund.

Trustees’ Compensation. The Fund’s Board of Trustees (“Board”) has adopted a compensation deferral plan for Independent Trustees that enables Trustees to elect to defer receipt of all or a portion of the annual compensation they are entitled to receive from the Fund. For purposes of determining the amount owed to the Trustees under the plan, deferred amounts are treated as though equal dollar amounts had been invested in shares of the Fund or in other Oppenheimer funds selected by the Trustees. The Fund purchases shares of the funds selected for deferral by the Trustees in amounts equal to his or her deemed investment, resulting in a Fund asset equal to the deferred compensation liability. Such assets are included as a component of “Other” within the asset section of the Statement of Assets and Liabilities. Deferral of Trustees’ fees under the plan will not affect the net assets of the Fund and will not materially affect the Fund’s assets, liabilities or net investment income per share. Amounts will

34 OPPENHEIMER MAIN STREET SMALL CAP FUND

8. Fees and Other Transactions with Affiliates (Continued)

be deferred until distributed in accordance with the compensation deferral plan.

Distribution and Service Plan (12b-1) Fees. Under its General Distributor’s Agreement with the Fund, OppenheimerFunds Distributor, Inc. (the “Distributor”) acts as the Fund’s principal underwriter in the continuous public offering of the Fund’s classes of shares.

Service Plan for Class A Shares. The Fund has adopted a Service Plan (the “Plan”) for Class A shares pursuant to Rule 12b-1 under the 1940 Act. Under the Plan, the Fund reimburses the Distributor for a portion of its costs incurred for services provided to accounts that hold Class A shares. Reimbursement is made periodically at an annual rate of up to 0.25% of the daily net assets of Class A shares of the Fund. The Distributor currently uses all of those fees to pay dealers, brokers, banks and other financial institutions periodically for providing personal service and maintenance of accounts of their customers that hold Class A shares. Any unreimbursed expenses the Distributor incurs with respect to Class A shares in any fiscal year cannot be recovered in subsequent periods. Fees incurred by the Fund under the Plan are detailed in the Statement of Operations.

Distribution and Service Plans for Class C and Class R Shares. The Fund has adopted Distribution and Service Plans (the “Plans”) for Class C and Class R shares pursuant to Rule 12b-1 under the 1940 Act to compensate the Distributor for distributing those share classes, maintaining accounts and providing shareholder services. Under the Plans, the Fund pays the Distributor an annual asset-based sales charge of 0.75% on Class C shares’ daily net assets and 0.25% on Class R shares’ daily net assets. The Fund also pays a service fee under the Plans at an annual rate of 0.25% of daily net assets. The Plans continue in effect from year to year only if the Fund’s Board of Trustees votes annually to approve their continuance at an in person meeting called for that purpose. Fees incurred by the Fund under the Plans are detailed in the Statement of Operations.

Sales Charges. Front-end sales charges and CDSC do not represent expenses of the Fund. They are deducted from the proceeds of sales of Fund shares prior to investment or from redemption proceeds prior to remittance, as applicable. The sales charges retained by the Distributor from the sale of shares and the CDSC retained by the Distributor on the redemption of shares is shown in the following table for the period indicated.


Six Months Ended	Class A Front-End Sales Charges Retained by Distributor		Class A Contingent Deferred Sales Charges Retained by Distributor		Class C Contingent Deferred Sales Charges Retained by Distributor		Class R Contingent Deferred Sales Charges Retained by Distributor

October 31, 2016		$28,789		$362		$1,995		$—

Waivers and Reimbursements of Expenses. The Manager has contractually agreed to waive fees and/or reimburse certain expenses so that “Expenses after payments, waivers and/

35 OPPENHEIMER MAIN STREET SMALL CAP FUND

NOTES TO FINANCIAL STATEMENTS Unaudited / Continued

8. Fees and Other Transactions with Affiliates (Continued)

or reimbursements and reduction to custodian expenses”, excluding expenses incurred directly or indirectly by the Fund as a result of investments in other investment companies, wholly-owned subsidiaries pooled investment vehicles and interest and fees from borrowings; will not exceed 1.25% for Class A shares, 2.25% for Class C shares, 0.80% for Class I shares, 1.75% for Class R shares and 0.90% for Class Y shares. During the reporting period, the Manager waived $24,733 for Class Y shares.

The Manager will waive fees and/or reimburse Fund expenses in an amount equal to the indirect management fees incurred through the Fund’s investment in IGMMF. During the reporting period, the Manager waived fees and/or reimbursed the Fund $5,786 for IGMMF management fees.

Waivers and/or reimbursements may be modified or terminated as set forth according to the terms in the prospectus.

9. Borrowing and Other Financing

Joint Credit Facility. A number of mutual funds managed by the Manager participate in a $1.3 billion revolving credit facility (the “Facility”) intended to provide short-term financing, if necessary, subject to certain restrictions in connection with atypical redemption activity. Expenses and fees related to the Facility are paid by the participating funds and are disclosed separately or as other expenses on the Statement of Operations. The Fund did not utilize the Facility during the reporting period.

10. Pending Litigation

In 2009, several putative class action lawsuits were filed and later consolidated before the U.S. District Court for the District of Colorado in connection with the investment performance of Oppenheimer Rochester California Municipal Fund (the “California Fund”), a fund advised by OppenheimerFunds, Inc. (“OFI”) and distributed by OppenheimerFunds Distributor, Inc. (“OFDI”). The plaintiffs asserted claims against OFI, OFDI and certain present and former trustees and officers of the California Fund under the federal securities laws, alleging, among other things, that the disclosure documents of the California Fund contained misrepresentations and omissions and the investment policies of the California Fund were not followed. An amended complaint and a motion to dismiss were filed, and in 2011, the court issued an order which granted in part and denied in part the defendants’ motion to dismiss. In October 2015, following a successful appeal by defendants and a subsequent hearing, the court granted plaintiffs’ motion for class certification and appointed class representatives and class counsel.

OFI and OFDI believe the suit is without merit; that it is premature to render any opinion as to the likelihood of an outcome unfavorable to them in the suit; and that no estimate can yet be made as to the amount or range of any potential loss. Furthermore, OFI believes that the suit should not impair the ability of OFI or OFDI to perform their respective duties to the Fund and that the outcome of the suit should not have any material effect on the operations of any of the Oppenheimer funds.

36 OPPENHEIMER MAIN STREET SMALL CAP FUND

BOARD APPROVAL OF THE FUND’S INVESTMENT ADVISORY

AND SUB-ADVISORY AGREEMENTS Unaudited

The Fund has entered into an investment advisory agreement with OFI Global Asset Management, Inc. (“OFI Global” or the “Adviser”), a wholly-owned subsidiary of OppenheimerFunds, Inc. (“OFI” or the “Sub-Adviser”) (“OFI Global” and “OFI” together the “Managers”) and OFI Global has entered into a sub-advisory agreement with OFI whereby OFI provides investment sub-advisory services to the Fund (collectively, the “Agreements”). Each year, the Board of Trustees (the “Board”), including a majority of the independent Trustees, is required to determine whether to approve the terms of the Agreements and the renewal thereof. The Investment Company Act of 1940, as amended, requires that the Board request and evaluate, and that the Managers provide, such information as may be reasonably necessary to evaluate the terms of the Agreements. The Board employs an independent consultant to prepare a report that provides information, including comparative information that the Board requests for that purpose. In addition to in-person meetings focused on this evaluation, the Board receives information throughout the year regarding Fund services, fees, expenses and performance.

The Managers and the independent consultant provided information to the Board on the following factors: (i) the nature, quality and extent of the Managers’ services, (ii) the comparative investment performance of the Fund and the Managers, (iii) the fees and expenses of the Fund, including comparative fee and expense information, (iv) the profitability of the Managers and their affiliates, including an analysis of the cost of providing services, (v) whether economies of scale are realized as the Fund grows and whether fee levels reflect these economies of scale for Fund investors and (vi) other benefits to the Managers from their relationship with the Fund. The Board was aware that there are alternatives to retaining the Managers.

Outlined below is a summary of the principal information considered by the Board as well as the Board’s conclusions.

Nature, Quality and Extent of Services. The Board considered information about the nature, quality and extent of the services provided to the Fund and information regarding the Managers’ key personnel who provide such services. The Managers’ duties include providing the Fund with the services of the portfolio managers and the Sub-Adviser’s investment team, who provide research, analysis and other advisory services in regard to the Fund’s investments; and securities trading services. OFI Global is responsible for oversight of third-party service providers; monitoring compliance with applicable Fund policies and procedures and adherence to the Fund’s investment restrictions; risk management; and oversight of the Sub-Adviser. OFI Global is also responsible for providing certain administrative services to the Fund. Those services include providing and supervising all administrative and clerical personnel who are necessary in order to provide effective corporate administration for the Fund; compiling and maintaining records with respect to the Fund’s operations; preparing and filing reports required by the U.S. Securities and Exchange Commission; preparing periodic reports regarding the operations of the Fund for its shareholders; preparing proxy materials for shareholder meetings; and preparing the registration statements required by federal and state securities laws for the sale of the Fund’s shares. OFI Global also provides the Fund with office space, facilities and equipment.

37 OPPENHEIMER MAIN STREET SMALL CAP FUND

BOARD APPROVAL OF THE FUND’S INVESTMENT ADVISORY

AND SUB-ADVISORY AGREEMENTS Unaudited / Continued

The Board also considered the quality of the services provided and the quality of the Managers’ resources that are available to the Fund. The Board took account of the fact that the Sub-Adviser has over fifty years of experience as an investment adviser and that its assets under management rank it among the top mutual fund managers in the United States. The Board evaluated the Managers’ advisory, administrative, accounting, legal, compliance and risk management services, and information the Board has received regarding the experience and professional qualifications of the Managers’ key personnel and the size and functions of its staff. In its evaluation of the quality of the portfolio management services provided, the Board considered the experience of Matthew Ziehl, Raymond Anello, Raman Vardharaj, Joy Budzinski, Kristin Ketner, Magnus Krantz and Adam Weiner, the portfolio managers for the Fund, and the Sub-Adviser’s investment team and analysts. The Board members also considered the totality of their experiences with the Managers as directors or trustees of the Fund and other funds advised by the Managers. The Board considered information regarding the quality of services provided by affiliates of the Managers, which the Board members have become knowledgeable about through their experiences with the Managers and in connection with the renewal of the Fund’s service agreements. The Board concluded, in light of the Managers’ experience, reputation, personnel, operations and resources that the Fund benefits from the services provided under the Agreements.

Investment Performance of the Managers and the Fund. Throughout the year, the Adviser provided information on the investment performance of the Fund, the Adviser and the Sub-Adviser, including comparative performance information. The Board also reviewed information, prepared by the Managers and by the independent consultant, comparing the Fund’s historical performance to relevant market indices and to the performance of other retail small blend funds. The Board noted that the Fund underperformed its category median for the one-year period, but also noted that the Fund was launched on May 17, 2013, and therefore has a relatively short performance history.

Fees and Expenses of the Fund. The Board reviewed the fees paid to the Adviser and the other expenses borne by the Fund. The Board noted that the Adviser, not the Fund, pays the Sub-Adviser’s fee under the sub-advisory agreement. The Board considered the comparability of the fees charged and the services provided to the Fund to the fees and services for other clients or accounts advised by the Adviser. The independent consultant provided comparative data in regard to the fees and expenses of the Fund and other retail small blend funds with comparable asset levels and distribution features. The Board also noted that the Fund’s contractual management fees and total expenses were lower than their respective peer group medians and category medians. The Board also considered that the Adviser has contractually agreed to waive fees and/or reimburse the Fund for certain expenses so that the total annual fund operating expenses as a percentage of average daily net assets will not exceed the following annual rates: 1.25% for Class A shares, 2.25% for Class C shares, 1.75% for Class R shares, 0.90% for Class Y shares, and 0.80% for Class I shares. This fee waiver may not be amended or withdrawn for one year from the date of the Fund’s prospectus, unless approved by the Board.

Economies of Scale and Profits Realized by the Managers. The Board considered information regarding the Managers’ costs in serving as the Fund’s investment adviser

38 OPPENHEIMER MAIN STREET SMALL CAP FUND

and sub-adviser, including the costs associated with the personnel and systems necessary to manage the Fund. The Board also considered that the Manager must be able to pay and retain experienced professional personnel at competitive rates to provide quality services to the Fund. The Board reviewed whether the Managers may realize economies of scale in managing and supporting the Fund. The Board noted that the Fund currently has management fee breakpoints, which are intended to share with Fund shareholders economies of scale that may exist as the Fund’s assets grow.

Other Benefits to the Managers. In addition to considering the profits realized by the Managers, the Board considered information that was provided regarding the direct and indirect benefits the Managers receive as a result of their relationship with the Fund, including compensation paid to the Managers’ affiliates and research provided to the Adviser in connection with permissible brokerage arrangements (soft dollar arrangements).

Conclusions. These factors were also considered by the independent Trustees meeting separately from the full Board, assisted by experienced counsel to the Fund and to the independent Trustees. Fund counsel and the independent Trustees’ counsel are independent of the Managers within the meaning and intent of the Securities and Exchange Commission Rules.

Based on its review of the information it received and its evaluations described above, the Board, including a majority of the independent Trustees, decided to continue the Agreements through August 31, 2017. In arriving at its decision, the Board did not identify any factor or factors as being more important than others, but considered all of the above information, and considered the terms and conditions of the Agreements, including the management fees, in light of all the surrounding circumstances.

39 OPPENHEIMER MAIN STREET SMALL CAP FUND

PORTFOLIO PROXY VOTING POLICIES AND GUIDELINES;

UPDATES TO STATEMENTS OF INVESTMENTS Unaudited

The Fund has adopted Portfolio Proxy Voting Policies and Guidelines under which the Fund votes proxies relating to securities (“portfolio proxies”) held by the Fund. A description of the Fund’s Portfolio Proxy Voting Policies and Guidelines is available (i) without charge, upon request, by calling the Fund toll-free at 1.800.CALL OPP (225.5677), (ii) on the Fund’s website at www.oppenheimerfunds.com, and (iii) on the SEC’s website at www.sec.gov. In addition, the Fund is required to file Form N-PX, with its complete proxy voting record for the 12 months ended June 30th, no later than August 31st of each year. The Fund’s voting record is available (i) without charge, upon request, by calling the Fund toll-free at 1.800.CALL OPP (225.5677), and (ii) in the Form N-PX filing on the SEC’s website at www.sec.gov.

The Fund files its complete schedule of portfolio holdings with the SEC for the first quarter and the third quarter of each fiscal year on Form N-Q. The Fund’s Form N-Q filings are available on the SEC’s website at www.sec.gov. Those forms may be reviewed and copied at the SEC’s Public Reference Room in Washington, D.C. Information on the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330.

Householding—Delivery of Shareholder Documents

This is to inform you about OppenheimerFunds’ “householding” policy. If more than one member of your household maintains an account in a particular fund, OppenheimerFunds will mail only one copy of the fund’s prospectus (or, if available, the fund’s summary prospectus), annual and semiannual report and privacy policy. The consolidation of these mailings, called householding, benefits your fund through reduced mailing expense, and benefits you by reducing the volume of mail you receive from OppenheimerFunds. Householding does not affect the delivery of your account statements.

Please note that we will continue to household these mailings for as long as you remain an OppenheimerFunds shareholder, unless you request otherwise. If you prefer to receive multiple copies of these materials, please call us at 1.800.CALL-OPP (225-5677). You may also notify us in writing or via email. We will begin sending you individual copies of the prospectus (or, if available, the summary prospectus), reports and privacy policy within 30 days of receiving your request to stop householding.

40 OPPENHEIMER MAIN STREET SMALL CAP FUND

OPPENHEIMER MAIN STREET SMALL CAP FUND


Trustees and Officers		Robert J. Malone, Chairman of the Board of Trustees and Trustee
		Jon S. Fossel, Trustee
		Richard F. Grabish, Trustee
		Beverly L. Hamilton, Trustee
		Victoria J. Herget, Trustee
		F. William Marshall, Jr., Trustee
		Karen L. Stuckey, Trustee
		James D. Vaughn, Trustee
		Matthew P. Ziehl, Vice President
		Raymond Anello, Vice President
		Raman Vardharaj, Vice President
		Joy Budzinski, Vice President
		Kristin Ketner, Vice President
		Magnus Krantz, Vice President
		Adam Weiner, Vice President
		Arthur P. Steinmetz, Trustee, President and Principal Executive Officer
		Cynthia Lo Bessette, Secretary and Chief Legal Officer
		Jennifer Foxson, Vice President and Chief Business Officer
		Mary Ann Picciotto, Chief Compliance Officer and Chief Anti-Money
		Laundering Officer
		Brian S. Petersen, Treasurer and Principal Financial & Accounting Officer

Manager		OFI Global Asset Management, Inc.

Sub-Adviser		OppenheimerFunds, Inc.

Distributor		OppenheimerFunds Distributor, Inc.

Transfer and Shareholder		OFI Global Asset Management, Inc.
Servicing Agent

Sub-Transfer Agent		Shareholder Services, Inc.
		DBA OppenheimerFunds Services

Independent Registered		KPMG LLP
Public Accounting Firm

Legal Counsel		Ropes & Gray LLP

		The financial statements included herein have been taken from the records of the Fund without examination of those records by the independent registered public accounting firm.

41 OPPENHEIMER MAIN STREET SMALL CAP FUND

As an Oppenheimer fund shareholder, you are entitled to know how we protect your personal information and how we limit its disclosure.

Information Sources

We obtain nonpublic personal information about our shareholders from the following sources:

●

Applications or other forms

●

When you create a user ID and password for online account access

●

When you enroll in eDocs Direct, our electronic document delivery service

●

Your transactions with us, our affiliates or others

●

Technologies on our website, including: “cookies” and web beacons, which are used to collect data on the pages you visit and the features you use.

If you visit oppenheimerfunds.com and do not log on to the secure account information areas, we do not obtain any personal information about you. When you do log on to a secure area, we do obtain your user ID and password to identify you. We also use this information to provide you with products and services you have requested, to inform you about products and services that you may be interested in and assist you in other ways.

We do not collect personal information through our website unless you willingly provide it to us, either directly by email or in those areas of the website that request information. In order to update your personal information (including your mailing address, email address and phone number) you must first log on and visit your user profile.

If you have set your browser to warn you before accepting cookies, you will receive the warning message with each cookie. You can refuse cookies by turning them off in your browser. However, doing so may limit your access to certain sections of our website.

We use cookies to help us improve and manage our website. For example, cookies help us recognize new versus repeat visitors to the site, track the pages visited, and enable some special features on the website. This data helps us provide a better service for our website visitors.

Protection of Information

We do not disclose any non-public personal information (such as names on a customer list) about current or former customers to anyone, except as permitted by law.

Disclosure of Information

Copies of confirmations, account statements and other documents reporting activity in your fund accounts are made available to your financial advisor (as designated by you). We may also use details about you and your investments to help us, our financial service affiliates, or firms that jointly market their financial products and services with ours, to better serve your investment needs or suggest educational material that may be of interest to you. If this requires us to provide you with an opportunity to “opt in” or “opt out” of such information sharing with a firm not affiliated with us, you will receive notification on how to do so, before any such sharing takes place.

Right of Refusal

We will not disclose your personal information to unaffiliated third parties (except as permitted by law), unless we first offer you a reasonable opportunity to refuse or “opt out” of such disclosure.

42 OPPENHEIMER MAIN STREET SMALL CAP FUND

Internet Security and Encryption

In general, the email services provided by our website are encrypted and provide a secure and private means of communication with us. To protect your own privacy, confidential and/or personal information should only be communicated via email when you are advised that you are using a secure website. As a security measure, we do not include personal or account information in non-secure emails, and we advise you not to send such information to us in non-secure emails. Instead, you may take advantage of the secure features of our website to encrypt your email correspondence. To do this, you will need to use a browser that supports Secure Sockets Layer (SSL) protocol.

●

All transactions, including redemptions, exchanges and purchases, are secured by SSL and 256-bit encryption. SSL is used to establish a secure connection between your PC and OppenheimerFunds’ server. It transmits information in an encrypted and scrambled format.

●

Encryption is achieved through an electronic scrambling technology that uses a “key” to code and then decode the data. Encryption acts like the cable converter box you may have on your television set. It scrambles data with a secret code so that no one can make sense of it while it is being transmitted. When the data reaches its destination, the same software unscrambles the data.

●

You can exit the secure area by either closing your browser, or for added security, you can use the Log Out button before you close your browser.

Other Security Measures

We maintain physical, electronic and procedural safeguards to protect your personal account information. Our employees and agents have access to that information only so that they may offer you products or provide services, for example, when responding to your account questions.

How You Can Help

You can also do your part to keep your account information private and to prevent unauthorized transactions. If you obtain a user ID and password for your account, safeguard that information. Also, take special precautions when accessing your account on a computer used by others.

Who We Are

This joint notice describes the privacy policies of the Oppenheimer funds, OppenheimerFunds, Inc., each of its investment adviser subsidiaries, OppenheimerFunds Distributor, Inc. and OFI Global Trust Co. It applies to all Oppenheimer fund accounts you presently have, or may open in the future, using your Social Security number—whether or not you remain a shareholder of our funds. This notice was last updated November 2016. In the event it is updated or changed, we will post an updated notice on our website at oppenheimerfunds.com. If you have any questions about this privacy policy, write to us at P.O. Box 5270, Denver, CO 80217-5270, email us by clicking on the Contact Us section of our website at oppenheimerfunds.com or call us at 1.800.CALL OPP (225.5677).

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47 OPPENHEIMER MAIN STREET SMALL CAP FUND


		Visit us at oppenheimerfunds.com for 24-hr access to account information and transactions or call us at 800.CALL OPP (800.225.5677) for 24-hr automated information and automated transactions. Representatives also available Mon–Fri 8am-8pm ET.
Visit Us oppenheimerfunds.com Call Us 800 225 5677 Follow Us
		Oppenheimer funds are distributed by OppenheimerFunds Distributor, Inc. 225 Liberty Street, New York, NY 10281-1008 ^© 2016 OppenheimerFunds Distributor, Inc. All rights reserved. RS1355.001.1016 December 22, 2016

Item 2. Code of Ethics.

Not applicable to semiannual reports.

Item 3. Audit Committee Financial Expert.

Not applicable to semiannual reports.

Item 4. Principal Accountant Fees and Services.

Not applicable to semiannual reports.

Item 5. Audit Committee of Listed Registrants

Not applicable.

Item 6. Schedule of Investments.

a) Not applicable. The complete schedule of investments is included in Item 1 of this Form N-CSR.

b) Not applicable.

Item 7. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies.

Not applicable.

Item 8. Portfolio Managers of Closed-End Management Investment Companies.

Not applicable.

Item 9. Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers.

Not applicable.

Item 10. Submission of Matters to a Vote of Security Holders.

The Fund’s Governance Committee Provisions with Respect to Nominations of Directors/Trustees to the Respective Boards

None

Item 11. Controls and Procedures.

Based on their evaluation of the registrant’s disclosure controls and procedures (as defined in rule 30a-3(c) under the Investment Company Act of 1940 (17 CFR 270.30a-3(c)) as of 10/31/2016, the registrant’s principal executive officer and principal financial officer found the registrant’s disclosure controls and procedures to provide reasonable assurances that information required to be disclosed by the registrant in the reports that it files under the Securities Exchange Act of 1934 (a) is accumulated and communicated to registrant’s management, including its principal executive officer and principal financial officer, to allow timely decisions regarding required disclosure, and (b) is recorded, processed, summarized and reported, within the time

periods specified in the rules and forms adopted by the U.S. Securities and Exchange Commission.

There have been no changes in the registrant’s internal controls over financial reporting that occurred during the registrant’s second fiscal quarter of the period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 12. Exhibits.

(a)	(1) Not applicable to semiannual reports.

(2) Exhibits attached hereto.

(3) Not applicable.

(b)	Exhibit attached hereto.

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.

Oppenheimer Main Street Small Cap Fund


By:		/s/ Arthur P. Steinmetz

		Arthur P. Steinmetz
		Principal Executive Officer
Date:		12/14/2016

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:		/s/ Arthur P. Steinmetz

		Arthur P. Steinmetz
		Principal Executive Officer
Date:		12/14/2016


By:		/s/ Brian S. Petersen

		Brian S. Petersen
		Principal Financial Officer
Date:		12/14/2016

Six Months Ended October 31, 2016

Year Ended April 29, 2016

Year Ended April 30, 2015

Period Ended April 30, 2014