Oppenheimer Short Duration Fund NCSR Certified annual shareholder report (management investment company)

Oppenheimer Short Duration Fund Inactive N-CSRCertified 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 811-22520

Oppenheimer Ultra-Short Duration 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: July 31

Date of reporting period: 7/31/2018

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			19

Statement of Operations			20

Statements of Changes in Net Assets			21

Financial Highlights			22

Notes to Financial Statements			25

Report of Independent Registered Public Accounting Firm			38

Federal Income Tax Information			39

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

Trustees and Officers			41

Privacy Notice			46

Class Y Shares

AVERAGE ANNUAL TOTAL RETURNS AT 7/31/18



	Class Y Shares of the Fund	ICE BofA Merrill Lynch 3-Month U.S. Treasury Bill Index
1-Year	1.58%	1.43%
5-Year	0.89	0.45
Since Inception (4/25/11)	0.82	0.34

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. 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). There is no sales charge for Class Y shares. See Fund prospectuses and summary prospectuses for more information on share classes and sales charges.

2 OPPENHEIMER ULTRA-SHORT DURATION FUND

Fund Performance Discussion

The Fund’s Class Y shares produced a total return of 1.58% over the one-year reporting period ended July 31, 2018, outperforming the 1.43% total return of its benchmark, the ICE BofA Merrill Lynch 3-Month U.S. Treasury Bill Index (the “Index”). Despite volatility among short term interest rates stemming from the Federal Reserve (“Fed”) hikes, the Fund continued to provide a higher level of current income versus alternatives. During the reporting period, the exposure to high grade corporate credit in both bonds and commercial paper allowed the Fund to outperform the Index. Adding to this outperformance was our positioning further out the curve, as the portfolio averaged about 140 days of effective duration.

MARKET OVERVIEW

In November of 2017, it was announced that Jerome Powell would become the 16th Chair of the Federal Reserve (the “Fed”). Many market participants believe his appointment by President Trump will allow for a continuation of a slow and steady rise

in the Fed Funds Rate. Mr. Powell has served on the Federal Reserve Board of Governors since 2012 and during this tenure has voted in harmony with the Federal Open Market Committee (FOMC) statements under both Janet Yellen and Ben Bernanke.

COMPARISON OF CHANGE IN VALUE OF $10,000 HYPOTHETICAL INVESTMENTS IN:

LOGO

3 OPPENHEIMER ULTRA-SHORT DURATION FUND

Current broader market and FOMC consensus is for two more hikes in 2018. We estimate the most likely scenario includes a hike at each of the September and December meetings. Should the markets remain stable and steady, many on the street are forecasting a total of four hikes in 2018. The more conservative consensus view puts the Fed Funds Rate in the 2.25% to 2.50% range at year end. Coupled with these hikes, the Fed continues to shrink its balance sheet down from $4.5 trillion, a move it started in October 2017. While the Fed has not indicated a balance sheet level it intends to hit, it has denoted the holdings will not return to pre-recession levels (less than $1 trillion). While the tapering to date has had minimal impact on the market, upcoming roll offs are expected to be higher in the third quarter of 2018 at $120 billion and then another $150 billion in the fourth quarter of 2018.

Another area of continued interest is in Treasury bill supply. Once the debt ceiling issue was resolved in the first part of the year, the Treasury restocked its cash balances in the first quarter of 2018 with record Treasury bill issuance. Due in part to the large bill issuance and talk around repatriation of overseas cash, the market witnessed a large spread difference in the 3-month London Interbank Offered Rate and Overnight Index Swap rate in the month of April.¹ The noise brought back memories of previous spikes, notably the 2008 financial crisis and the European debt crisis. However, this time around, credit concerns were not the driving force. Rather it was the shear supply of bills and the

uncertainties around repatriation.

From a credit standpoint, credit spreads have continued to ebb and flow in a tight range. More recently we have seen spreads tighten with an increase in demand and a summer lull in supply. The tax reform bill from earlier this year continues to provide a little more flexibility in managing a firm’s financials in the investment grade space. We remain cautiously optimistic and keep our watchful eye on macro items (i.e., inflation, unemployment, wages, U.S. dollar, central banks’ balance sheets, etc.) that could also be impactful to our overall investment views. Further, with merger and acquisitions in constant flux, fundamentals remain paramount for our investment selection.

FUND REVIEW

The Fund continues to invest most of its assets in securities with maturities of one year or less. This focus generally allows the Fund to have relatively low price volatility and increases its inherent liquidity. At the same time, we continued to complement investments in money market securities with investment grade short-term corporate notes and bonds with maturities of one to three years. To further mitigate the interest rate risk, we maintain a short position in Treasury future contracts, which would benefit in value should short Treasury rates rise. We continue to be positioned for more rate hikes in 2018 and into 2019.

4 OPPENHEIMER ULTRA-SHORT DURATION FUND

STRATEGY & OUTLOOK

Our strategy continues to be one that seeks income with reduced volatility. We believe in our investment process and our strong fundamental credit analysis. Our outlook is for

two more hikes in 2018. We believe the Fund is well positioned to take advantage of these higher rates as long as the Fed continues on a path of slow and steady hikes.

1. The London Interbank Offered Rate (LIBOR) is the average interest rate estimated by leading banks in London that they would be charged if borrowing from other banks. It is a primary benchmark for short- term interest rates around the world. The Overnight Index Swap rate is the difference between the overnight lending rates set by central banks and the three-month LIBOR. The Overnight Index Swap rate tracks the relationship between an expected three-month Fed Funds Rate and three-month LIBOR.

LOGO

Christopher Proctor, CFA

Portfolio Manager

LOGO

Adam S. Wilde, CFA

Portfolio Manager

5 OPPENHEIMER ULTRA-SHORT DURATION FUND

Top Holdings and Allocations

PORTFOLIO ALLOCATION


Non-Convertible Corporate Bonds and Notes			57.9%
Short-Term Notes			35.4
Asset-Backed Securities			6.7

Portfolio holdings and allocations are subject to change. Percentages are as of July 31, 2018, and are based on the total market value of investments.

For more current Fund holdings, please visit oppenheimerfunds.com.

6 OPPENHEIMER ULTRA-SHORT DURATION FUND

Share Class Performance

AVERAGE ANNUAL TOTAL RETURNS AS OF 7/31/18


	Inception Date		1-Year			5-Year			Since Inception
Class A (OSDAX)		4/25/11		1.51	%		0.83	%		0.72	%
Class I (OSDIX)		11/28/14		1.58			N/A			1.41
Class Y (OSDYX)		4/25/11		1.58			0.89			0.82


STANDARDIZED YIELDS		UNSUBSIDIZED STANDARDIZED YIELDS
For the 30 Days Ended 7/31/18		For the 30 Days Ended 7/31/18
Class A	2.32%	Class A	2.26%
Class I	2.40	Class I	2.28
Class Y	2.39	Class Y	2.26

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). There is no sales charge for Class A, Class I and Class Y shares. Class A shares are not currently available for purchase. Returns for periods of less than one year are cumulative and not annualized. See Fund prospectuses and summary prospectuses for more information on share classes.

Standardized yield is based on an SEC-standardized formula designed to approximate the Fund’s annualized hypothetical current income from securities less expenses for the 30-day period ended July 31, 2018 and that date’s net asset value (for all share classes). Each result is compounded semiannually and then annualized. Falling share prices will tend to artificially raise yields. The unsubsidized standardized yield is computed under an SEC-standardized formula based on net income earned for the 30-day period ended July 31, 2018. The calculation excludes any expense reimbursements and thus may result in a lower yield.

The Fund’s performance is compared to the performance of the ICE Bank of America (BofA) Merrill Lynch 3-month U.S. Treasury Bill Index, an index of short-term U.S. Government securities with a remaining term to final maturity of less than three months. 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 views in the Fund Performance Discussion represent the opinions of this Fund’s portfolio manager(s) and are not intended as investment advice or to predict or depict the performance of any investment. These views are as of the close of business on July 31, 2018, and are

7 OPPENHEIMER ULTRA-SHORT DURATION FUND

subject to change based on subsequent developments. The Fund’s portfolio and strategies are subject to change.

Before investing in any of the Oppenheimer funds, investors should carefully consider a fund’s investment objectives, risks, charges and expenses. 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 ULTRA-SHORT DURATION 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 July 31, 2018.

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 July 31, 2018” 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 ULTRA-SHORT DURATION FUND


Actual	Beginning Account Value February 1, 2018		Ending Account Value July 31, 2018		Expenses Paid During 6 Months Ended July 31, 2018
Class A	$	1,000.00	$	1,009.80	$	1.70
Class I		1,000.00		1,008.20		1.25
Class Y		1,000.00		1,010.20		1.30

Hypothetical (5% return before expenses)
Class A		1,000.00		1,023.11		1.71
Class I		1,000.00		1,023.55		1.26
Class Y		1,000.00		1,023.51		1.31

Expenses are equal to the Fund’s annualized expense ratio for that class, multiplied by the average account value over the period, multiplied by 181/365 (to reflect the one-half year period). Those annualized expense ratios, excluding indirect expenses from affiliated funds, based on the 6-month period ended July 31, 2018 are as follows:

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 ULTRA-SHORT DURATION FUND

STATEMENT OF INVESTMENTS July 31, 2018


	Principal Amount		Value
Asset-Backed Securities—6.7%
AmeriCredit Automobile Receivables Trust:
Series 2017-2, Cl. A2A, 1.65%, 9/18/20	$	580,207	$	578,629
Series 2017-3, Cl. A2A, 1.69%, 12/18/20		1,205,581		1,200,768
Series 2018-1, Cl. A2A, 2.71%, 7/19/21		1,000,000		999,026
BMW Vehicle Lease Trust, Series 2017-2, Cl. A2A, 1.80%, 2/20/20		842,093		838,831
Capital Auto Receivables Asset Trust:
Series 2018-1, Cl. A2A, 2.54%, 10/20/20¹		2,000,000		1,997,797
Series 2018-1, Cl. A2B, 2.256% [US0001M+17], 10/20/20^1,2		1,000,000		999,503
CarMax Auto Owner Trust, Series 2018-2, Cl. A2, 2.73%, 8/16/21		2,250,000		2,247,263
Drive Auto Receivables Trust:
Series 2018-1, Cl. A2, 2.23%, 4/15/20		1,632,131		1,631,264
Series 2018-1, Cl. A3, 2.42%, 1/15/21		1,000,000		998,592
Ford Credit Auto Lease Trust, Series 2018-A, Cl. A2A, 2.71%, 12/15/20		2,000,000		1,998,523
GM Financial Automobile Leasing Trust, Series 2017-1, Cl.
A2A, 1.67%, 9/20/19		606,238		605,280
GM Financial Consumer Automobile Receivables Trust:
Series 2018-2, Cl. A2A, 2.55%, 5/17/21		2,000,000		1,997,692
Series 2018-2, Cl. A2B, 2.202% [US0001M+13], 5/17/21²		1,000,000		1,000,065
Santander Drive Auto Receivables Trust:
Series 2018-2, Cl. A2A, 2.58%, 10/15/20		2,500,000		2,497,329
Series 2018-2, Cl. A2B, 2.322% [US0001M+25], 10/15/20²		2,500,000		2,500,918
World Omni Auto Receivables Trust, Series 2018-B, Cl. A2, 2.57%, 7/15/21		1,500,000		1,497,010
World Omni Automobile Lease Securitization Trust, Series 2018-A, Cl. A2, 2.59%, 11/16/20		2,500,000		2,495,833

Total Asset-Backed Securities (Cost $26,114,979)				26,084,323
Corporate Bonds and Notes—57.7%
Consumer Discretionary—6.3%
Automobiles—5.3%
American Honda Finance Corp.:
2.505% [US0003M+15] Sr. Unsec. Nts., 11/13/19²		1,000,000		1,001,618
2.65% Sr. Unsec. Nts., 2/12/21		2,000,000		1,977,234
BMW US Capital LLC:
2.747% [US0003M+41] Sr. Unsec. Nts., 4/12/21^1,2		2,000,000		2,006,263
3.10% Sr. Unsec. Nts., 4/12/21¹		500,000		496,826
Daimler Finance North America LLC:
1.50% Sr. Unsec. Nts., 7/5/19¹		3,000,000		2,961,692
2.25% Sr. Unsec. Nts., 7/31/19¹		1,000,000		993,423
2.913% [US0003M+55] Sr. Unsec. Nts., 5/4/21^1,2		1,900,000		1,906,948
Harley-Davidson Financial Services, Inc., 2.40% Sr. Unsec. Nts., 9/15/19¹		2,040,000		2,023,076
Toyota Motor Corp., 3.183% Sr. Unsec. Nts., 7/20/21		2,000,000		2,005,566
Toyota Motor Credit Corp.:
2.20% Sr. Unsec. Nts., 1/10/20		1,500,000		1,483,680
2.435% [US0003M+10] Sr. Unsec. Nts., 7/25/19²		3,000,000		2,999,999

11 OPPENHEIMER ULTRA-SHORT DURATION FUND

STATEMENT OF INVESTMENTS Continued


	Principal Amount		Value
Automobiles (Continued)
Toyota Motor Credit Corp.: (Continued) 2.596% [US0003M+26] Sr. Unsec. Nts., 4/17/20²	$	1,000,000	$	1,002,957

				20,859,282
Hotels, Restaurants & Leisure—0.1%
Starbucks Corp., 2.20% Sr. Unsec. Nts., 11/22/20		500,000		489,503
Internet & Catalog Retail—0.5%
Amazon.com, Inc., 1.90% Sr. Unsec. Nts., 8/21/20		2,000,000		1,961,185
Media—0.4%
21st Century Fox America, Inc., 8.25% Sr. Unsec. Nts., 8/10/18		1,400,000		1,401,715
Consumer Staples—1.2%
Beverages—0.7%
Diageo Capital plc:
2.566% [US0003M+24] Sr. Unsec. Nts., 5/18/20²		1,500,000		1,502,235
3.00% Sr. Unsec. Nts., 5/18/20		1,000,000		1,000,116

				2,502,351
Food Products—0.5%
JM Smucker Co. (The), 2.20% Sr. Unsec. Nts., 12/6/19		1,000,000		989,368
Mondelez International, Inc., 3.00% Sr. Unsec. Nts., 5/7/20		1,000,000		997,938

				1,987,306
Financials—44.2%
Capital Markets—4.3%
Goldman Sachs Bank USA (New York), 3.20% Sr. Unsec. Nts., 6/5/20		2,000,000		2,003,258
Goldman Sachs Group, Inc. (The), 7.50% Sr. Unsec. Nts., 2/15/19		2,263,000		2,322,291
Morgan Stanley:
2.45% Sr. Unsec. Nts., 2/1/19		1,700,000		1,698,650
2.903% [US0003M+55] Sr. Unsec. Nts., 2/10/21²		500,000		501,012
5.625% Sr. Unsec. Nts., 9/23/19		2,236,000		2,301,443
7.30% Sr. Unsec. Nts., 5/13/19		1,000,000		1,034,495
UBS AG (London):
2.20% Sr. Unsec. Nts., 6/8/20¹		2,000,000		1,961,066
2.901% [US0003M+58] Sr. Unsec. Nts., 6/8/20^1,2		1,000,000		1,004,133
UBS AG (Stamford CT), 2.375% Sr. Unsec. Nts., 8/14/19		4,000,000		3,981,407

				16,807,755
Commercial Banks—37.4%
ABN AMRO Bank NV:
2.10% Sr. Unsec. Nts., 1/18/19¹		2,000,000		1,995,786
2.65% Sr. Unsec. Nts., 1/19/21¹		2,000,000		1,965,270
2.752% [US0003M+41] Sr. Unsec. Nts., 1/19/21^1,2		2,000,000		2,001,820
2.973% [US0003M+64] Sr. Unsec. Nts., 1/18/19^1,2		2,000,000		2,005,600

12 OPPENHEIMER ULTRA-SHORT DURATION FUND


	Principal Amount		Value
Commercial Banks (Continued)
Australia & New Zealand Banking Group Ltd.:
2.25% Sr. Unsec. Nts., 12/19/19¹	$	1,500,000	$	1,485,479
2.576% [US0003M+25] Sr. Unsec. Nts., 12/19/19^1,2		1,500,000		1,502,318
2.689% [US0003M+32] Sr. Unsec. Nts., 11/9/20^1,2		1,000,000		1,001,546
3.08% [US0003M+75] Sr. Unsec. Nts., 11/16/18^1,2		1,000,000		1,001,912
Australia & New Zealand Banking Group Ltd. (New York), 2.25% Sr. Unsec. Nts., 11/9/20		1,000,000		978,095
Bank of America Corp., 7.625% Sr. Unsec. Nts., 6/1/19		2,000,000		2,078,445
Bank of Montreal:
2.10% Sr. Unsec. Nts., 12/12/19		1,800,000		1,779,535
2.781% [US0003M+44] Sr. Unsec. Nts., 6/15/20²		1,500,000		1,506,399
2.797% [US0003M+46] Sr. Unsec. Nts., 4/13/21²		1,000,000		1,004,499
2.926% [US0003M+60] Sr. Unsec. Nts., 12/12/19²		1,200,000		1,206,560
3.10% Sr. Unsec. Nts., 4/13/21		1,000,000		995,604
Bank of Nova Scotia (The):
2.50% Sr. Unsec. Nts., 1/8/21		2,000,000		1,962,921
2.629% [US0003M+29] Sr. Unsec. Nts., 1/8/21²		2,000,000		1,996,585
2.996% [US0003M+66] Sr. Unsec. Nts., 6/14/19²		1,500,000		1,507,171
BNP Paribas/BNP Paribas US Medium-Term Note Program LLC, 2.40% Sr. Unsec. Nts., 12/12/18		1,000,000		999,635
Branch Banking & Trust Co.:
2.10% Sr. Unsec. Nts., 1/15/20		1,250,000		1,233,329
2.25% Sr. Unsec. Nts., 6/1/20		1,000,000		982,728
2.52% [US0003M+22] Sr. Unsec. Nts., 6/1/20²		1,000,000		998,944
2.789% [US0003M+45] Sr. Unsec. Nts., 1/15/20²		1,250,000		1,254,970
Citibank NA:
2.10% Sr. Unsec. Nts., 6/12/20		1,000,000		980,785
2.595% [US0003M+26] Sr. Unsec. Nts., 9/18/19²		1,000,000		1,000,471
2.705% [US0003M+35] Sr. Unsec. Nts., 2/12/21²		2,000,000		1,999,408
2.826% [US0003M+50] Sr. Unsec. Nts., 6/12/20²		1,000,000		1,005,015
Citigroup, Inc., 2.05% Sr. Unsec. Nts., 6/7/19		1,000,000		993,529
Cooperatieve Rabobank UA, 4.75% Sr. Unsec. Nts., 1/15/20¹		1,370,000		1,400,607
Danske Bank AS:
2.20% Sr. Unsec. Nts., 3/2/20¹		1,000,000		982,389
2.831% [US0003M+51] Sr. Unsec. Nts., 3/2/20^1,2		1,000,000		1,002,980
2.894% [US0003M+58] Sr. Unsec. Nts., 9/6/19^1,2		3,000,000		3,011,956
DNB Bank ASA:
2.125% Sr. Unsec. Nts., 10/2/20¹		4,000,000		3,894,044
2.707% [US0003M+37] Sr. Unsec. Nts., 10/2/20^1,2		3,000,000		3,006,771
HSBC USA, Inc., 2.375% Sr. Unsec. Nts., 11/13/19		3,500,000		3,475,223
ING Bank NV:
2.30% Sr. Unsec. Nts., 3/22/19¹		2,900,000		2,890,921
2.953% [US0003M+61] Sr. Unsec. Nts., 8/15/19^1,2		1,250,000		1,254,653
Lloyds Bank plc:
2.853% [US0003M+49] Sr. Unsec. Nts., 5/7/21²		2,500,000		2,510,815
3.30% Sr. Unsec. Nts., 5/7/21		1,000,000		997,076
Mitsubishi UFJ Trust & Banking Corp., 2.45% Sr. Unsec. Nts., 10/16/19¹		2,500,000		2,482,055
Mizuho Bank Ltd., 2.45% Sr. Unsec. Nts., 4/16/19¹		2,000,000		1,995,394

13 OPPENHEIMER ULTRA-SHORT DURATION FUND

STATEMENT OF INVESTMENTS Continued


	Principal Amount		Value
Commercial Banks (Continued)
MUFG Bank Ltd., 2.35% Sr. Unsec. Nts., 9/8/19¹	$	3,500,000	$	3,472,000
National Australia Bank Ltd.:
2.687% [US0003M+35] Sr. Unsec. Nts., 1/12/21^1,2		2,000,000		1,999,606
2.839% [US0003M+51] Sr. Unsec. Nts., 5/22/20^1,2		2,000,000		2,010,171
2.921% [US0003M+59] Sr. Unsec. Nts., 1/10/20^1,2		1,500,000		1,510,069
3.119% [US0003M+78] Sr. Unsec. Nts., 1/14/19^1,2		1,000,000		1,003,152
National Australia Bank Ltd. (New York):
2.00% Sr. Unsec. Nts., 1/14/19		1,000,000		997,933
2.50% Sr. Unsec. Nts., 1/12/21		2,000,000		1,959,582
National Bank of Canada:
2.15% Sr. Unsec. Nts., 6/12/20		2,000,000		1,961,622
2.20% Sr. Unsec. Nts., 11/2/20		1,000,000		974,807
2.886% [US0003M+56] Sr. Unsec. Nts., 6/12/20²		2,000,000		2,011,832
2.936% [US0003M+60] Sr. Unsec. Nts., 1/17/20²		2,000,000		2,012,193
Nordea Bank AB:
2.125% Sr. Unsec. Nts., 5/29/20¹		1,000,000		979,640
2.789% [US0003M+47] Sr. Unsec. Nts., 5/29/20^1,2		1,000,000		1,003,289
2.954% [US0003M+62] Sr. Unsec. Nts., 9/30/19^1,2		2,000,000		2,011,927
PNC Bank NA:
2.45% Sr. Unsec. Nts., 11/5/20		3,000,000		2,947,251
2.719% [US0003M+40] Sr. Unsec. Nts., 12/7/18²		1,000,000		1,001,410
Royal Bank of Canada:
2.125% Sr. Unsec. Nts., 3/2/20		2,000,000		1,972,352
2.15% Sr. Unsec. Nts., 10/26/20		2,000,000		1,956,717
2.575% [US0003M+24] Sr. Unsec. Nts., 10/26/20²		1,000,000		997,827
3.049% [US0003M+71] Sr. Unsec. Nts., 4/15/19²		1,000,000		1,004,925
Skandinaviska Enskilda Banken AB:
2.751% [US0003M+43] Sr. Unsec. Nts., 5/17/21^1,2		4,000,000		4,002,536
2.903% [US0003M+57] Sr. Unsec. Nts., 9/13/19^1,2		1,000,000		1,004,709
3.25% Sr. Unsec. Nts., 5/17/21¹		1,500,000		1,491,818
Societe Generale SA:
2.625% Sr. Unsec. Nts., 10/1/18		2,000,000		2,000,810
2.625% Sr. Unsec. Nts., 9/16/20¹		2,460,000		2,416,172
3.417% [US0003M+108] Sr. Unsec. Nts., 10/1/18²		1,000,000		1,001,991
Sumitomo Mitsui Banking Corp.:
2.092% Sr. Unsec. Nts., 10/18/19		1,000,000		987,199
2.643% [US0003M+31] Sr. Unsec. Nts., 10/18/19²		1,000,000		1,001,275
3.012% [US0003M+67] Sr. Unsec. Nts., 10/19/18²		2,000,000		2,003,069
Svenska Handelsbanken AB:
2.681% [US0003M+36] Sr. Unsec. Nts., 9/8/20²		3,000,000		3,005,986
2.804% [US0003M+49] Sr. Unsec. Nts., 9/6/19²		1,000,000		1,004,205
Toronto-Dominion Bank (The):
2.492% [US0003M+15] Sr. Unsec. Nts., 10/24/19²		1,000,000		999,266
2.55% Sr. Unsec. Nts., 1/25/21		1,000,000		983,051
2.753% [US0003M+42] Sr. Unsec. Nts., 1/18/19²		600,000		601,079
2.756% [US0003M+43] Sr. Unsec. Nts., 6/11/21²		2,000,000		2,004,507
3.00% Sr. Unsec. Nts., 6/11/20		1,000,000		998,685
3.187% [US0003M+84] Sr. Unsec. Nts., 1/22/19²		2,000,000		2,007,528

14 OPPENHEIMER ULTRA-SHORT DURATION FUND


	Principal Amount		Value
Commercial Banks (Continued)
US Bank NA (Cincinnati OH):
2.35% Sr. Unsec. Nts., 1/23/20	$	1,000,000	$	990,284
2.487% [US0003M+14] Sr. Unsec. Nts., 10/23/20²		2,000,000		1,998,365
Wells Fargo Bank NA:
2.40% Sr. Unsec. Nts., 1/15/20		3,500,000		3,467,664
2.649% [US0003M+31] Sr. Unsec. Nts., 1/15/21²		3,500,000		3,499,287
Westpac Banking Corp.:
2.623% [US0003M+28] Sr. Unsec. Nts., 5/15/20²		1,500,000		1,501,556
2.65% Sr. Unsec. Nts., 1/25/21		1,500,000		1,475,538
2.675% [US0003M+34] Sr. Unsec. Nts., 1/25/21²		2,000,000		2,002,277
3.05% Sr. Unsec. Nts., 5/15/20		1,000,000		997,780
3.07% [US0003M+74] Sr. Unsec. Nts., 11/23/18²		1,000,000		1,002,314

				146,566,499
Consumer Finance—2.5%
American Express Co.:
2.20% Sr. Unsec. Nts., 10/30/20		1,500,000		1,467,352
2.669% [US0003M+33] Sr. Unsec. Nts., 10/30/20²		1,000,000		1,000,863
2.846% [US0003M+52.5] Sr. Unsec. Nts., 5/17/21²		1,500,000		1,508,718
3.375% Sr. Unsec. Nts., 5/17/21		1,000,000		1,001,422
American Express Credit Corp., 2.684% [US0003M+33] Sr. Unsec. Nts., 5/3/19²		1,000,000		1,001,484
Capital One Financial Corp.:
2.40% Sr. Unsec. Nts., 10/30/20		2,000,000		1,953,024
2.789% [US0003M+45] Sr. Unsec. Nts., 10/30/20²		2,000,000		2,000,236

				9,933,099
Industrials—3.2%
Aerospace & Defense—1.0%
BAE Systems Holdings, Inc., 6.375% Sr. Unsec. Nts., 6/1/19¹		1,091,000		1,121,421
General Dynamics Corp.:
2.736% [US0003M+38] Sr. Unsec. Nts., 5/11/21²		1,000,000		1,005,973
2.875% Sr. Unsec. Nts., 5/11/20		2,000,000		1,996,406

				4,123,800
Machinery—2.2%
Caterpillar Financial Services Corp.:
2.51% [US0003M+18] Sr. Unsec. Nts., 5/15/20²		1,500,000		1,501,499
2.571% [US0003M+23] Sr. Unsec. Nts., 3/15/21²		1,500,000		1,502,505
2.90% Sr. Unsec. Nts., 3/15/21		1,500,000		1,493,492
2.95% Sr. Unsec. Nts., 5/15/20		1,000,000		999,733
John Deere Capital Corp.:
2.566% [US0003M+24] Sr. Unsec. Nts., 3/12/21²		1,500,000		1,500,163
2.875% Sr. Unsec. Nts., 3/12/21		1,500,000		1,487,284

				8,484,676

15 OPPENHEIMER ULTRA-SHORT DURATION FUND

STATEMENT OF INVESTMENTS Continued


	Principal Amount		Value
Information Technology—1.5%
IT Services—1.5%
Western Union Co. (The), 3.129% [US0003M+80] Sr. Unsec. Nts., 5/22/19²	$	6,000,000	$	6,016,512
Telecommunication Services—0.8%
Diversified Telecommunication Services—0.8%
AT&T, Inc., 5.20% Sr. Unsec. Nts., 3/15/20		3,000,000		3,095,737
Utilities—0.5%
Electric Utilities—0.5%
Eversource Energy, 2.50% Sr. Unsec. Nts., 3/15/21		2,000,000		1,959,651

Total Corporate Bonds and Notes (Cost $227,219,884)				226,189,071
Short-Term Notes—35.2%
Chemicals—2.1%
Cabot Corp., 2.343%, 8/1/18^1,3,4		350,000		349,979
Nutrien Ltd.:
2.461%, 9/28/18^1,3,4		1,200,000		1,194,881
2.49%, 8/10/18^1,3,4		2,000,000		1,998,623
2.511%, 9/11/18^1,3,4		4,600,000		4,586,245

				8,129,728
Computers & Peripherals—1.3%
HP, Inc., 2.647%, 10/15/18⁴		5,000,000		4,977,918
Diversified Telecommunication Services—1.2%
AT&T, Inc.:
2.636%, 9/6/18^1,3,4		2,000,000		1,995,260
3.093%, 5/30/19^1,3,4		3,000,000		2,927,911

				4,923,171
Electric Utilities—3.9%
Commonwealth Edison Co., 2.375%, 8/6/18^3,4		5,000,000		4,998,183
Puget Sound Energy, Inc., 2.303%, 8/16/18⁴		2,600,000		2,597,414
Sempra Energy:
2.563%, 8/27/18^3,4		1,750,000		1,747,042
2.564%, 8/28/18^3,4		2,500,000		2,495,617
2.617%, 9/18/18^3,4		3,500,000		3,488,814

				15,327,070
Energy Equipment & Services—3.5%
Schlumberger Holdings Corp.:
2.41%, 9/25/18^1,3,4		4,000,000		3,985,490
2.514%, 9/24/18^1,3,4		2,000,000		1,992,887
TransCanada PipeLines Ltd., 2.585%, 9/17/18^1,3,4		8,000,000		7,974,986

				13,953,363

16 OPPENHEIMER ULTRA-SHORT DURATION FUND


	Principal Amount		Value
Food & Staples Retailing—1.0%
Walgreens Boots Alliance, Inc., 2.576%, 8/2/18⁴	$	3,800,000	$	3,799,539
Health Care Providers & Services—0.8%
McKesson Corp., 2.303%, 8/7/18^1,3,4		3,050,000		3,048,692
Hotels, Restaurants & Leisure—1.9%
Marriott International, Inc.:
2.468%, 8/21/18^1,3,4		2,150,000		2,147,177
2.489%, 9/21/18^1,3,4		5,500,000		5,481,267

				7,628,444
Household Durables—1.0%
Whirlpool Corp., 2.515%, 9/28/18⁴		4,000,000		3,984,385
Leasing & Factoring—2.5%
Hitachi Capital America Corp., 2.455%, 8/2/18⁴		10,000,000		9,998,803
Media—3.3%
Interpublic Group Cos., 2.395%, 8/2/18^1,3,4		7,700,000		7,699,076
WPP CP, 2.769%, 10/3/18^1,3,4		5,000,000		4,978,658

				12,677,734
Metals & Mining—1.0%
Glencore Funding, 2.526%, 10/23/18^3,4		4,000,000		3,976,359
Multi-Utilities—1.3%
CenterPoint Energy Resources Corp., 2.577%, 9/10/18^1,3,4		5,000,000		4,986,931
Oil, Gas & Consumable Fuels—0.8%
Eni Finance USA, Inc., 2.759%, 1/28/19^3,4		3,000,000		2,959,169
Personal Products—0.2%
BAT International Finance plc, 2.718%, 9/11/18^3,4		600,000		598,377
Semiconductor Equipment & Products—1.8%
QUALCOMM, Inc.:
2.364%, 8/29/18^1,3,4		3,000,000		2,995,000
2.42%, 10/2/18^1,3,4		4,000,000		3,984,446

				6,979,446
Telephone Utilities—4.3%
Bell Canada, Inc.:
2.567%, 10/29/18^3,4		4,000,000		3,975,450
2.597%, 8/10/18^3,4		1,000,000		999,389
2.705%, 10/15/18^3,4		2,000,000		1,989,850
Telus Corp., 2.623%, 11/28/18^1,4		6,000,000		5,947,700
Vodafone Group plc:
2.598%, 9/25/18⁴		1,200,000		1,195,572

17 OPPENHEIMER ULTRA-SHORT DURATION FUND

STATEMENT OF INVESTMENTS Continued


	Principal Amount			Value
Telephone Utilities (Continued)
Vodafone Group plc: (Continued)
2.621%, 10/22/18⁴	$	2,800,000		$	2,784,009

					16,891,970
Tobacco—1.8%
BAT International Finance plc, 2.719%, 9/5/18^3,4		7,200,000			7,183,534
Transportation Infrastructure—1.5%
ERAC USA Finance Co., 2.355%, 8/28/18^1,3,4		6,000,000			5,989,481
Total Short-Term Notes (Cost $137,992,947)					138,014,114
Total Investments, at Value (Cost $391,327,810)		99.6	%		390,287,508
Net Other Assets (Liabilities)		0.4			1,629,104

Net Assets		100.0	%	$	391,916,612

Footnotes to Statement of Investments

1. Represents securities sold under Rule 144A, which are exempt from registration under the Securities Act of 1933, as amended. These securities have been determined to be liquid under guidelines established by the Board of Trustees. These securities amount to $149,523,428 or 38.15% of the Fund’s net assets at period end.

2. Represents the current interest rate for a variable or increasing rate security, determined as [Referenced Rate + Basis-point spread].

3. Security issued in an exempt transaction without registration under the Securities Act of 1933. Such securities amount to $102,728,774 or 26.21% of the Fund’s net assets, and have been determined to be liquid pursuant to guidelines adopted by the Board of Trustees.

4. Current yield as of period end.

Futures Contracts as of July 31, 2018

Description

Buy/Sell

Expiration
Date

Number

of Contracts

Notional Amount
(000’s)

Value

Unrealized
Appreciation/
(Depreciation)

United States Treasury Nts., 2 yr.

Sell

9/28/18

400

USD 84,574

84,550,000

$ 24,392


Glossary:
Definitions
US0001M		ICE LIBOR USD 1 Month
US0003M		ICE LIBOR USD 3 Month

Exchange Abbreviations
ICE LIBOR		Intercontinental Exchange London Interbank Offered Rate

See accompanying Notes to Financial Statements.

18 OPPENHEIMER ULTRA-SHORT DURATION FUND

STATEMENT OF ASSETS AND LIABILITIES July 31, 2018


Assets
Investments, at value (cost $391,327,810) —see accompanying statement of investments	$	390,287,508
Cash		147,398
Cash used for collateral on futures		231,750
Receivables and other assets:
Interest		1,291,957
Shares of beneficial interest sold		39,125
Other		47,531

Total assets		392,045,269
Liabilities
Payables and other liabilities:
Trustees’ compensation		33,580
Shares of beneficial interest redeemed		20,509
Dividends		15,352
Variation margin payable		6,250
Shareholder communications		3,162
Other		49,804

Total liabilities		128,657
Net Assets	$	391,916,612


Composition of Net Assets

Par value of shares of beneficial interest		$78,374

Additional paid-in capital		393,342,265

Accumulated net investment income		37,790

Accumulated net realized loss on investments		(525,907	)
Net unrealized depreciation on investments		(1,015,910	)

Net Assets	$	391,916,612


Net Asset Value Per Share
Class A Shares:

Net asset value and redemption price per share (based on net assets of $99,913 and 20,000 shares of beneficial interest outstanding)		$5.00

Class I Shares:

Net asset value, redemption price and offering price per share (based on net assets of $10,425,438 and 2,060,289 shares of beneficial interest outstanding)		$5.06

Class Y Shares:

Net asset value, redemption price and offering price per share (based on net assets of $381,391,261 and 76,293,865 shares of beneficial interest outstanding)		$5.00

See accompanying Notes to Financial Statements.

19 OPPENHEIMER ULTRA-SHORT DURATION FUND

STATEMENT OF

OPERATIONS For the Year Ended July 31, 2018


Investment Income
Interest	$	14,235,223

Expenses
Management fees		2,198,197
Transfer and shareholder servicing agent fees:
Class A		51
Class I		3,359
Class Y		360,718
Shareholder communications:
Class I		11
Class Y		14,671
Legal, auditing and other professional fees		105,631
Trustees’ compensation		41,758
Borrowing fees		26,304
Custodian fees and expenses		5,140
Other		37,648

Total expenses		2,793,488
Less waivers and reimbursements of expenses		(935,277	)

Net expenses		1,858,211

Net Investment Income		12,377,012
Realized and Unrealized Gain (Loss)
Net realized gain (loss) on:
Investment transactions in unaffiliated companies		(1,817,815	)
Futures contracts		1,357,551

Net realized loss		(460,264	)
Net change in unrealized appreciation/depreciation on:
Investment transactions in unaffiliated companies		(1,708,149	)
Futures contracts		(3,595	)

Net change in unrealized appreciation/depreciation		(1,711,744	)

Net Increase in Net Assets Resulting from Operations	$	10,205,004

See accompanying Notes to Financial Statements.

20 OPPENHEIMER ULTRA-SHORT DURATION FUND

STATEMENTS OF CHANGES IN NET ASSETS


	Year Ended July 31, 2018			Year Ended July 31, 2017
Operations
Net investment income	$	12,377,012		$	6,126,758
Net realized gain (loss)		(460,264	)		115,615
Net change in unrealized appreciation/depreciation		(1,711,744	)		328,225

Net increase in net assets resulting from operations		10,205,004			6,570,598

Dividends and/or Distributions to Shareholders
Dividends from net investment income:
Class A		(1,697	)		(1,112)
Class I		(195,487	)		(99,755)
Class Y		(12,193,178	)		(6,025,698)

		(12,390,362	)		(6,126,565)

Beneficial Interest Transactions
Net increase (decrease) in net assets resulting from beneficial interest transactions:
Class A		—			—
Class I		344,717			(3,690,275	)
Class Y		(379,951,203	)		366,136,008
		(379,606,486	)		362,445,733

Net Assets
Total increase (decrease)		(381,791,844	)		362,889,766
Beginning of period		773,708,456			410,818,690

End of period (including accumulated net investment income of $37,790 and $20,170, respectively)	$	391,916,612		$	773,708,456

See accompanying Notes to Financial Statements.

21 OPPENHEIMER ULTRA-SHORT DURATION FUND

FINANCIAL HIGHLIGHTS


Class A	Year Ended July 31, 2018			Year Ended July 31, 2017			Year Ended July 31, 2016¹			Year Ended July 31, 2015¹			Year Ended July 31, 2014¹
Per Share Operating Data
Net asset value, beginning of period		$5.01			$5.01			$5.00			$5.01			$5.00
Income (loss) from investment operations:
Net investment income²		0.08			0.06			0.04			0.02			0.01
Net realized and unrealized gain (loss)		(0.01)			0.00³			0.01			(0.01)			0.01

Total from investment operations		0.07			0.06			0.05			0.01			0.02
Dividends and/or distributions to shareholders:
Dividends from net investment income		(0.08)			(0.06)			(0.04)			(0.02)			(0.01)
Distributions from net realized gain		0.00			0.00			0.00			(0.00)	³		(0.00)	³

Total dividends and/or distributions to shareholders		(0.08)			(0.06)			(0.04)			(0.02)			(0.01)
Net asset value, end of period		$5.00			$5.01			$5.01			$5.00			$5.01


Total Return, at Net Asset Value⁴		1.51%			1.12%			0.96%			0.21%			0.37%

Ratios/Supplemental Data
Net assets, end of period (in thousands)		$100			$100			$100			$100			$100
Average net assets (in thousands)		$100			$100			$100			$100			$100
Ratios to average net assets:⁵
Net investment income		1.62%			1.11%			0.86%			0.29%			0.24%
Expenses excluding specific expenses listed below		0.38%			0.38%			0.38%			0.38%			0.37%
Interest and fees from borrowings		0.00%	⁶		0.00%	⁶		0.00%	⁶		0.00%	⁶		0.00%

Total expenses		0.38%			0.38%⁷			0.38%⁷			0.38%⁷			0.37%⁷
Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses		0.33%			0.32%			0.33%			0.33%			0.32%
Portfolio turnover rate		72%			52%			90%			106%			86%

1. On August 7, 2015, the Fund effected a share split as described in Note 11 of the accompanying Notes. Per share data prior to this date has been restated to give effect to the share split.

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

3. Less than $0.005 per share.

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:


Year Ended July 31, 2017	0.38	%
Year Ended July 31, 2016	0.38	%
Year Ended July 31, 2015	0.38	%
Year Ended July 31, 2014	0.37	%

See accompanying Notes to Financial Statements.

22 OPPENHEIMER ULTRA-SHORT DURATION FUND


Class I	Year Ended July 31, 2018			Year Ended July 31, 2017			Year Ended July 31, 2016¹			Period Ended July 31, 2015^1,2
Per Share Operating Data
Net asset value, beginning of period		$5.07			$5.01			$5.00			$5.01
Income (loss) from investment operations:
Net investment income³		0.08			0.06			0.05			0.02
Net realized and unrealized gain (loss)		(0.00)	⁴		0.06			0.01			(0.01)

Total from investment operations		0.08			0.12			0.06			0.01
Dividends and/or distributions to shareholders:
Dividends from net investment income		(0.09)			(0.06)			(0.05)			(0.02)
Distributions from net realized gain		0.00			0.00			0.00			(0.00)	⁴

Total dividends and/or distributions to shareholders		(0.09)			(0.06)			(0.05)			(0.02)
Net asset value, end of period		$5.06			$5.07			$5.01			$5.00


Total Return, at Net Asset Value⁵		1.58%			2.38%			1.04%			0.19%

Ratios/Supplemental Data
Net assets, end of period (in thousands)		$10,426			$10,109			$13,789			$10
Average net assets (in thousands)		$10,216			$8,238			$5,453			$10
Ratios to average net assets:⁶
Net investment income		1.67%			1.21%			1.02%			0.42%
Expenses excluding specific expenses listed below		0.40%			0.36%			0.37%			0.35%
Interest and fees from borrowings		0.00%	⁷		0.00%	⁷		0.00%	⁷		0.00%	⁷

Total expenses		0.40%			0.36%	⁸		0.37%	⁸		0.35%	⁸
Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses		0.28%			0.25%			0.25%			0.25%
Portfolio turnover rate		72%			52%			90%			106%

1. On August 7, 2015, the Fund effected a share split as described in Note 11 of the accompanying Notes. Per share data prior to this date has been restated to give effect to the share split.

2. For the period from November 28, 2014 (inception of offering) to July 31, 2015.

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:


Year Ended July 31, 2017	0.40	%
Year Ended July 31, 2016	0.37	%
Period Ended July 31, 2015	0.35	%

See accompanying Notes to Financial Statements.

23 OPPENHEIMER ULTRA-SHORT DURATION FUND

FINANCIAL HIGHLIGHTS Continued


Class Y	Year Ended July 31, 2018		Year Ended July 31, 2017		Year Ended July 31, 2016¹		Year Ended July 31, 2015¹		Year Ended July 31, 2014¹
Per Share Operating Data
Net asset value, beginning of period		$5.01		$5.01		$5.00		$5.01		$5.01
Income (loss) from investment operations:
Net investment income²		0.08		0.06		0.05		0.02		0.02
Net realized and unrealized gain (loss)		(0.00)³		0.00³		0.01		(0.01)		0.00³

Total from investment operations		0.08		0.06		0.06		0.01		0.02
Dividends and/or distributions to shareholders:
Dividends from net investment income		(0.09)		(0.06)		(0.05)		(0.02)		(0.02)
Distributions from net realized gain		0.00		0.00		0.00		(0.00)³		(0.00)³

Total dividends and/or distributions to shareholders		(0.09)		(0.06)		(0.05)		(0.02)		(0.02)
Net asset value, end of period		$5.00		$5.01		$5.01		$5.00		$5.01


Total Return, at Net Asset Value⁴		1.58%		1.19%		1.05%		0.29%		0.34%

Ratios/Supplemental Data
Net assets, end of period (in thousands)		$381,391		$763,499		$396,930		$276,780		$599,559
Average net assets (in thousands)		$720,645		$501,550		$295,268		$431,806		$583,205
Ratios to average net assets:⁵
Net investment income		1.69%		1.20%		0.94%		0.35%		0.31%
Expenses excluding specific expenses listed below		0.38%		0.38%		0.39%		0.38%		0.38%
Interest and fees from borrowings		0.00%⁶		0.00%⁶		0.00%⁶		0.00%⁶		0.00%

Total expenses		0.38%		0.38%⁷		0.39%⁷		0.38%⁷		0.38%⁷
Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses		0.25%		0.25%		0.25%		0.25%		0.25%
Portfolio turnover rate		72%		52%		90%		106%		86%

1. On August 7, 2015, the Fund effected a share split as described in Note 11 of the accompanying Notes. Per share data prior to this date has been restated to give effect to the share split.

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

3. Less than $0.005 per share.

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:


Year Ended July 31, 2017	0.38	%
Year Ended July 31, 2016	0.39	%
Year Ended July 31, 2015	0.38	%
Year Ended July 31, 2014	0.38	%

See accompanying Notes to Financial Statements.

24 OPPENHEIMER ULTRA-SHORT DURATION FUND

NOTES TO FINANCIAL STATEMENTS July 31, 2018

1. Organization

Oppenheimer Ultra-Short Duration 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 income. 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 I and Class Y shares. Class A shares are sold at their offering price, which is the net asset value per share without any initial sales charge. Class A shares are currently not available for purchase. Class I and Class Y shares are sold to certain institutional investors without a front-end sales charge, 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.

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.

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 distributions, if any, are declared daily and paid monthly. Capital gain distributions, if any, are declared and paid annually or at other times as determined necessary by the Manager.

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 value of the securities received. Withholding taxes on foreign dividends, if any, and capital gains taxes on foreign investments, if any, have been provided for in accordance with the

25 OPPENHEIMER ULTRA-SHORT DURATION FUND

NOTES TO FINANCIAL STATEMENTS Continued

2. Significant Accounting Policies (Continued)

Fund’s understanding of the applicable tax rules and regulations. Interest income, if any, 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.

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 securities and from cash outflows resulting from unanticipated shareholder redemption activity. The Fund pays interest to its custodian on such cash overdraft at a rate equal to the Prime Rate plus 0.35%. 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, including any net realized gain on investments not offset by capital loss carryforwards, if any, 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 July 31, 2018, including open tax years, and does not believe there are any uncertain tax positions requiring recognition in the Fund’s financial statements.

The tax components of capital shown in the following table represent distribution requirements the Fund must satisfy under the income tax regulations, losses the Fund may be able to offset against income and gains realized in future years and unrealized appreciation or depreciation of securities and other investments for federal income tax purposes.

26 OPPENHEIMER ULTRA-SHORT DURATION FUND

2. Significant Accounting Policies (Continued)

Undistributed

Net Investment

Income

Undistributed
Long-Term
Gain

Accumulated
Loss
Carryforward^1,2,3

Net Unrealized
Depreciation
Based on cost of
Securities and
Other Investments
for Federal Income
Tax Purposes

$86,722

—

501,517

1,040,300

1. At period end, the Fund had $501,517 of net capital loss carryforward available to offset future realized capital gains, if any, and thereby reduce future taxable gain distributions.

2. During the reporting period, the Fund did not utilize any capital loss carryforward.

3. During the previous reporting period, the Fund utilized $ 360,320 of capital loss carryforward to offset capital gains realized in that fiscal year.

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 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.

Accordingly, the following amounts have been reclassified for the reporting period. Net assets of the Fund were unaffected by the reclassifications.


Increase to Accumulated Net Investment Income	Increase to Accumulated Net Realized Loss on Investments
$30,970		$30,970

The tax character of distributions paid during the reporting periods:


	Year Ended July 31, 2018		Year Ended July 31, 2017
Distributions paid from:
Ordinary income	$	12,384,111	$	6,126,565
Long-term capital gain		6,251		—

Total	$	12,390,362	$	6,126,565

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.

27 OPPENHEIMER ULTRA-SHORT DURATION FUND

NOTES TO FINANCIAL STATEMENTS Continued

2. Significant Accounting Policies (Continued)


Federal tax cost of securities	$	391,327,808
Federal tax cost of other investments		(84,550,000	)

Total federal tax cost	$	306,777,808

Gross unrealized appreciation	$	298,578
Gross unrealized depreciation		(1,338,878	)

Net unrealized depreciation	$	(1,040,300	)

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.

New Accounting Pronouncement. In March 2017, Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”), ASU 2017-08. This provides guidance related to the amortization period for certain purchased callable debt securities held at a premium. The ASU is effective for annual periods beginning after December 15, 2018, and interim periods within those annual periods. The Manager is evaluating the impacts of these changes on the financial statements.

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 least quarterly or more frequently, if necessary.

Valuation Methods and Inputs

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

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

Corporate and government debt securities (of U.S. or foreign issuers) and municipal debt securities, short-term notes, mortgage-backed securities, collateralized mortgage obligations, and asset-backed securities are valued at the mean between the bid and asked prices utilizing

28 OPPENHEIMER ULTRA-SHORT DURATION FUND

3. Securities Valuation (Continued)

evaluated prices obtained from third party pricing services or broker-dealers who may use matrix pricing methods to determine the evaluated prices. Pricing services generally price debt securities assuming orderly transactions of an institutional “round lot” size, but some trades may occur in smaller, “odd lot” sizes, sometimes at lower prices than institutional round lot trades. Standard inputs generally considered by third-party pricing vendors include reported trade data, broker-dealer price quotations, benchmark yields, issuer spreads on comparable securities, the credit quality, yield, maturity, as well as other appropriate factors.

Futures contracts and futures options traded on a commodities or futures exchange will be valued at the final settlement price or official closing price on the principal exchange as reported by such principal exchange at its trading session ending at, or most recently prior to, the time when the Fund’s assets are valued.

Securities for which market quotations are not readily available, or when a significant event has occurred that would materially affect the value of the security, are 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. Those standardized fair valuation 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.

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 may be 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 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).

29 OPPENHEIMER ULTRA-SHORT DURATION FUND

NOTES TO FINANCIAL STATEMENTS Continued

3. Securities Valuation (Continued)

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

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:
Asset-Backed Securities	$	—	$	26,084,323	$	—	$	26,084,323
Corporate Bonds and Notes		—		226,189,071		—		226,189,071
Short-Term Notes		—		138,014,114		—		138,014,114

Total Investments, at Value		—		390,287,508		—		390,287,508
Other Financial Instruments:
Futures Contracts		24,392		—		—		24,392

Total Assets	$	24,392	$	390,287,508	$	—	$	390,311,900

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.

For the reporting period, there were no transfers between levels.

4. Investments and Risks

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

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 90% 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

30 OPPENHEIMER ULTRA-SHORT DURATION FUND

5. Market Risk Factors (Continued)

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. Use of Derivatives

The Fund’s investment objective not only permits the Fund to purchase investment securities, it also allows the Fund to enter into various types of derivatives contracts, including, but not limited to, futures contracts, forward currency exchange contracts, credit default swaps, interest rate swaps, total return swaps, variance swaps and purchased and written options. In doing so, the Fund will employ strategies in differing combinations to permit it to increase, decrease, or change the level or types of exposure to market risk factors. These instruments may allow the Fund to pursue its objectives more quickly and efficiently than if it were to make direct purchases or sales of securities capable of effecting a similar response to market factors. Such contracts may be entered into through a bilateral over-the-counter (“OTC”) transaction, or through a securities or futures exchange and cleared through a clearinghouse.

Derivatives may have little or no initial cash investment relative to their market value exposure and therefore can produce significant gains or losses in excess of their cost due to changes in the market risk factors and the overall market. This use of embedded leverage allows the Fund to increase its market value exposure relative to its net assets and can substantially increase the volatility of the Fund’s performance. In instances where the Fund is using derivatives to decrease, or hedge, exposures to market risk factors for securities held by the Fund, there are also risks that those derivatives may not perform as expected resulting in losses for the combined or hedged positions. Some derivatives have the potential for unlimited

31 OPPENHEIMER ULTRA-SHORT DURATION FUND

NOTES TO FINANCIAL STATEMENTS Continued

6. Use of Derivatives (Continued)

loss, regardless of the size of the Fund’s initial investment.

Additional associated risks from investing in derivatives also exist and potentially could have significant effects on the valuation of the derivative and the Fund. Typically, the associated risks are not the risks that the Fund is attempting to increase or decrease exposure to, per its investment objectives, but are the additional risks from investing in derivatives. Examples of these associated risks are liquidity risk, which is the risk that the Fund will not be able to sell the derivative in the open market in a timely manner, and counterparty credit risk, which is the risk that the counterparty will not fulfill its obligation to the Fund.

The Fund’s actual exposures to these market risk factors and associated risks during the period are discussed in further detail, by derivative type, below.

Futures Contracts

A futures contract is a commitment to buy or sell a specific amount of a commodity, financial instrument or currency at a negotiated price on a stipulated future date. The Fund may buy and sell futures contracts and may also buy or write put or call options on these futures contracts. Futures contracts and options thereon are generally entered into on a regulated futures exchange and cleared through a clearinghouse associated with the exchange.

Upon entering into a futures contract, the Fund is required to deposit either cash or securities (initial margin) in an amount equal to a certain percentage of the contract value in an account registered in the futures commission merchant’s name. Subsequent payments (variation margin) are paid to or from the futures commission merchant each day equal to the daily changes in the contract value. Such payments are recorded as unrealized gains and losses. Should the Fund fail to make requested variation margin payments, the futures commission merchant can gain access to the initial margin to satisfy the Fund’s payment obligations.

Futures contracts are reported on a schedule following the Statement of Investments. Securities held by a futures commission merchant to cover initial margin requirements on open futures contracts are noted in the Statement of Investments. Cash held by a futures commission merchant to cover initial margin requirements on open futures contracts and the receivable and/or payable for the daily mark to market for the variation margin are noted in the Statement of Assets and Liabilities. The net change in unrealized appreciation and depreciation is reported in the Statement of Operations. Realized gains (losses) are reported in the Statement of Operations at the closing or expiration of futures contracts.

The Fund may purchase and/or sell financial futures contracts and options on futures contracts to gain exposure to, or decrease exposure to interest rate risk, equity risk, foreign exchange rate risk, volatility risk, or commodity risk.

During the reporting period, the Fund had an ending monthly average market value of $81,734,736 on futures contracts sold.

Additional associated risks of entering into futures contracts (and related options) include the possibility that there may be an illiquid market where the Fund is unable to liquidate the contract or enter into an offsetting position and, if used for hedging purposes, the risk that the price of the contract will correlate imperfectly with the prices of the Fund’s securities.

32 OPPENHEIMER ULTRA-SHORT DURATION FUND

6. Use of Derivatives (Continued)

Counterparty Credit Risk. Derivative positions are subject to the risk that the counterparty will not fulfill its obligation to the Fund. The Fund intends to enter into derivative transactions with counterparties that the Manager believes to be creditworthy at the time of the transaction.

For financial reporting purposes, the Fund does not offset derivative assets and derivative liabilities that are subject to netting arrangements in the Statement of Assets and Liabilities. Bankruptcy or insolvency laws of a particular jurisdiction may impose restrictions on or prohibitions against the right of offset in bankruptcy, insolvency or other events.

The Fund’s risk of loss from counterparty credit risk on exchange-traded derivatives cleared through a clearinghouse and for centrally cleared swaps is generally considered lower than as compared to OTC derivatives. However, counterparty credit risk exists with respect to initial and variation margin deposited/paid by the Fund that is held in futures commission merchant, broker and/or clearinghouse accounts for such exchange-traded derivatives and for centrally cleared swaps.

With respect to centrally cleared swaps, such transactions will be submitted for clearing, and if cleared, will be held in accounts at futures commission merchants or brokers that are members of clearinghouses. While brokers, futures commission merchants and clearinghouses are required to segregate customer margin from their own assets, in the event that a broker, futures commission merchant or clearinghouse becomes insolvent or goes into bankruptcy and at that time there is a shortfall in the aggregate amount of margin held by the broker, futures commission merchant or clearinghouse for all its customers, U.S. bankruptcy laws will typically allocate that shortfall on a pro-rata basis across all the broker’s, futures commission merchant’s or clearinghouse’s customers, potentially resulting in losses to the Fund.

There is the risk that a broker, futures commission merchant or clearinghouse will decline to clear a transaction on the Fund’s behalf, and the Fund may be required to pay a termination fee to the executing broker with whom the Fund initially enters into the transaction. Clearinghouses may also be permitted to terminate centrally cleared swaps at any time. The Fund is also subject to the risk that the broker or futures commission merchant will improperly use the Fund’s assets deposited/paid as initial or variation margin to satisfy payment obligations of another customer. In the event of a default by another customer of the broker or futures commission merchant, the Fund might not receive its variation margin payments from the clearinghouse, due to the manner in which variation margin payments are aggregated for all customers of the broker/futures commission merchant.

Collateral and margin requirements differ by type of derivative. Margin requirements are established by the broker, futures commission merchant or clearinghouse for exchange-traded and cleared derivatives, including centrally cleared swaps. Brokers, futures commission merchants and clearinghouses can ask for margin in excess of the regulatory minimum, or increase the margin amount, in certain circumstances.

For financial reporting purposes, cash collateral that has been pledged to cover obligations of the Fund, if any, is reported separately on the Statement of Assets and Liabilities as cash pledged as collateral. Non-cash collateral pledged by the Fund, if any, is noted in

33 OPPENHEIMER ULTRA-SHORT DURATION FUND

NOTES TO FINANCIAL STATEMENTS Continued

6. Use of Derivatives (Continued)

the Statement of Investments. Generally, the amount of collateral due from or to a party must exceed a minimum transfer amount threshold (e.g. $250,000) before a transfer has to be made. To the extent amounts due to the Fund from its counterparties are not fully collateralized, contractually or otherwise, the Fund bears the risk of loss from counterparty nonperformance.

The following table presents the valuations of derivative instruments by risk exposure as reported within the Statement of Assets and Liabilities at period end:


	Liability Derivatives
Derivatives Not Accounted for as Hedging Instruments	Statement of Assets and Liabilities Location	Value
Interest rate contracts	Variation margin payable	$ 6,250*

*Includes only the current day’s variation margin. Prior variation margin movements have been reflected in cash on the Statement of Assets and Liabilities upon receipt or payment.

The effect of derivative instruments on the Statement of Operations is as follows:


Amount of Realized Gain or (Loss) Recognized on Derivatives
Derivatives Not Accounted for as Hedging Instruments	Futures contracts
Interest rate contracts	$	1,357,551

Amount of Change in Unrealized Gain or (Loss) Recognized on Derivatives
Derivatives Not Accounted for as Hedging Instruments	Futures contracts
Interest rate contracts	$	(3,595	)

7. 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:

Year Ended July 31, 2018

Year Ended July 31, 2017

Shares

Amount

Shares

Amount

Class A

Sold

—

Dividends and/or distributions reinvested

—

Redeemed

—

Net increase

—

34 OPPENHEIMER ULTRA-SHORT DURATION FUND


7. Shares of Beneficial Interest (Continued)
	Year Ended July 31, 2018						Year Ended July 31, 2017
	Shares			Amount			Shares			Amount
Class I
Sold		36,323		$	183,800			2,571,186		$	12,999,988
Dividends and/or distributions reinvested		35,634			180,425			17,805			90,270
Redeemed		(3,855	)		(19,508	)		(3,349,975	)		(16,780,533)

Net increase (decrease)		68,102		$	344,717			(760,984	)	$	(3,690,275)



Class Y
Sold		271,666,629		$	1,359,868,315			149,137,239		$	747,177,572
Dividends and/or distributions reinvested		2,430,597			12,162,533			1,202,337			6,023,706
Redeemed		(350,120,932	)		(1,751,982,051	)		(77,258,537	)		(387,065,270)

Net increase (decrease)		(76,023,706	)	$	(379,951,203	)		73,081,039		$	366,136,008

8. Purchases and Sales of Securities

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


	Purchases		Sales
Investment securities		$261,666,861		$331,572,100
U.S. government and government agency obligations		—		1,981,320

9. 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 of 0.30%.

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, which shall be calculated after any applicable fee waivers. 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

35 OPPENHEIMER ULTRA-SHORT DURATION FUND

NOTES TO FINANCIAL STATEMENTS Continued

9. Fees and Other Transactions with Affiliates (Continued)

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

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. The Fund does not currently charge such fees on Class A shares.

Waivers and Reimbursements of Expenses. The Manager has contractually agreed to waive fees and/or reimburse expenses to limit the Fund’s “Expenses after payments, waivers and/or reimbursements and reduction to custodian expenses” (excluding any applicable dividend expense, taxes, interest and fees from borrowing, any subsidiary expenses, Acquired Fund Fees and Expenses, brokerage commissions, and certain other Fund expenses) so that, as percentages of average daily net assets, those expenses will not exceed the annual rate of 0.65% for Class A shares and 0.25% for Class I and Class Y shares, respectively. The Manager will also waive a portion of the advisory fee on Class A shares to the same extent that it waives any of the advisory fee on Class I or Class Y shares.

During the reporting period, the Manager waived fees and/or reimbursed the Fund as follows:

36 OPPENHEIMER ULTRA-SHORT DURATION FUND

9. Fees and Other Transactions with Affiliates (Continued)


Class A			$51
Class I			12,122
Class Y			923,104

This fee waiver and/or expense reimbursement may not be amended or withdrawn for one year from the date of the Fund’s prospectus, unless approved by the Board.

10. Borrowings and Other Financing

Joint Credit Facility. A number of mutual funds managed by the Manager participate in a $1.95 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.

11. Share Split

As of the close of business on August 7, 2015, the Fund implemented a 2 for 1 share split. This share split effectively increased the number of outstanding shares for the Fund. As a result, shareholders’ accounts reflect additional shares with a lower net asset value per share. While the number of shares increased, neither the Fund’s holdings nor the total value of shareholders’ investments was affected. Per share data in the financial highlights prior to

August 7, 2015, has been adjusted to give effect to this share split.

37 OPPENHEIMER ULTRA-SHORT DURATION FUND

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Shareholders and Board of Trustees

Oppenheimer Ultra-Short Duration Fund:

Opinion on the Financial Statements

We have audited the accompanying statement of assets and liabilities of Oppenheimer Ultra-Short Duration Fund (the “Fund”), including the statement of investments, as of July 31, 2018, the related statement of operations for the year then ended, the statements of changes in net assets for each of the years in the two year period then ended, and the related notes (collectively, the “financial statements”) and the financial highlights for each of the years or periods in the five year period then ended. In our opinion, the financial statements and financial highlights present fairly, in all material respects, the financial position of the Fund as of July 31, 2018, the results of its operations for the year then ended, the changes in its net assets for each of the years in the two year period then ended, and the financial highlights for each of the years or periods in the five year period then ended, in conformity with U.S. generally accepted accounting principles.

Basis for Opinion

These financial statements and financial highlights are the responsibility of the Fund’s management. Our responsibility is to express an opinion on these financial statements and financial highlights based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (“PCAOB”) and are required to be independent with respect to the Fund in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements and financial highlights are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements and financial highlights, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements and financial highlights. Such procedures also included confirmation of securities owned as of July 31, 2018, by correspondence with the custodian and brokers, or by other appropriate auditing procedures. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements and financial highlights. We believe that our audits provide a reasonable basis for our opinion.

KPMGLLP

We have not been able to determine the specific year that we began serving as the auditor of one or more Oppenheimer Funds investment companies, however we are aware that we have served as the auditor of one or more Oppenheimer Funds investment companies since at least 1969.

Denver, Colorado

September 26, 2018

38 OPPENHEIMER ULTRA-SHORT DURATION FUND

FEDERAL INCOME TAX INFORMATION Unaudited

In early 2018, if applicable, shareholders of record received information regarding all dividends and distributions paid to them by the Fund during calendar year 2017.

None of the dividends paid by the Fund during the reporting period are eligible for the corporate dividend-received deduction.

Dividends, if any, paid by the Fund during the reporting period which are not designated as capital gain distributions, may be eligible for lower individual income tax rates to the extent that the Fund has received qualified dividend income as stipulated by recent tax legislation. In early 2018, shareholders of record received information regarding the percentage of distributions that are eligible for lower individual income tax rates. The amount will be the maximum amount allowed.

Recent tax legislation allows a regulated investment company to designate distributions not designated as capital gain distributions, as either interest related dividends or short-term capital gain dividends, both of which are exempt from the U.S. withholding tax applicable to non U.S. taxpayers. For the reporting period, the maximum amount allowable but not less than $8,541,235 of the ordinary distributions to be paid by the Fund qualifies as an interest related dividend.

The foregoing information is presented to assist shareholders in reporting distributions received from the Fund to the Internal Revenue Service. Because of the complexity of the federal regulations which may affect your individual tax return and the many variations in state and local tax regulations, we recommend that you consult your tax advisor for specific guidance.

39 OPPENHEIMER ULTRA-SHORT DURATION FUND

PORTFOLIO PROXY VOTING POLICIES AND GUIDELINES;

UPDATES TO STATEMENT 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 ULTRA-SHORT DURATION FUND

TRUSTEES AND OFFICERS Unaudited


Name, Position(s) Held with the Fund, Length of Service, Year of Birth		Principal Occupation(s) During the Past 5 Years; Other Trusteeships/Directorships Held.

INDEPENDENT TRUSTEES		The address of each Trustee in the chart below is 6803 S. Tucson Way, Centennial, Colorado 80112-3924. Each Trustee serves for an indefinite term, or until his or her resignation, retirement, death or removal. Each of the Trustees in the chart below oversees 56 portfolios in the OppenheimerFunds complex.

Robert J. Malone, Chairman of the Board of Trustees (since 2016) and Trustee (since 2011) Year of Birth: 1944		Chairman - Colorado Market of MidFirst Bank (since January 2015); Chairman of the Board (2012-2016) and Director (August 2005-January 2016) of Jones International University (educational organization); Trustee of the Gallagher Family Foundation (non-profit organization) (2000-2016); Chairman, Chief Executive Officer and Director of Steele Street Bank Trust (commercial banking) (August 2003-January 2015); Director of Opera Colorado Foundation (non-profit organization) (2008-2012); Director of Colorado UpLIFT (charitable organization) (1986-2010); Director of Jones Knowledge, Inc. (2006-2010); Former Chairman of U.S. Bank-Colorado (subsidiary of U.S. Bancorp and formerly Colorado National Bank) (July 1996-April 1999); Director of Commercial Assets, Inc. (real estate investment trust) (1993-2000); Director of U.S. Exploration, Inc. (oil and gas exploration) (1997-February 2004); Chairman of the Board (1991-1994) and Trustee (1985-1994) of Regis University; and Chairman of the Board (1990-1991) and Member (1984-1999) of Young Presidents Organization. Mr. Malone has served on the Boards of certain Oppenheimer funds since 2002, during which time he has become familiar with the Fund’s (and other Oppenheimer funds’) financial, accounting, regulatory and investment matters and has contributed to the Board’s deliberations.

Andrew J. Donohue, Trustee (since 2017) Year of Birth: 1950		Director, Mutual Fund Directors Forum (since February 2018); Of Counsel, Shearman & Sterling LLP (since September 2017); Chief of Staff of the U.S. Securities and Exchange Commission (regulator) (June 2015-February 2017); Managing Director and Investment Company General Counsel of Goldman Sachs (investment bank) (November 2012-May 2015); Partner at Morgan Lewis & Bockius, LLP (law firm) (March 2011-October 2012); Director of the Division of Investment Management of U.S. Securities and Exchange Commission (regulator) (May 2006-November 2010); Global General Counsel of Merrill Lynch Investment Managers (investment firm) (May 2003-May 2006); General Counsel (October 1991-November 2001) and Executive Vice President (January 1993-November 2001) of OppenheimerFunds, Inc. (investment firm) (June 1991-November 2001). Mr. Donohue has served on the Boards of certain Oppenheimer funds since 2017, during which time he has become familiar with the Fund’s (and other Oppenheimer funds’) financial, accounting, regulatory and investment matters and has contributed to the Board’s deliberations.

Richard F. Grabish, Trustee (since 2011) Year of Birth: 1948		Formerly Senior Vice President and Assistant Director of Sales and Marketing (March 1997-December 2007), Director (March 1987-December 2007) and Manager of Private Client Services (June 1985-June 2005) of A.G. Edwards & Sons, Inc. (broker/dealer and investment firm); Chairman and Chief Executive Officer of A.G. Edwards Trust Company, FSB (March 2001-December 2007); President and Vice Chairman of A.G. Edwards Trust Company, FSB (investment adviser) (April 1987-March 2001); President of A.G. Edwards Trust Company, FSB (investment adviser) (June 2005-December 2007). Mr. Grabish has served on the Boards of certain Oppenheimer funds since 2001, during which time he has become familiar with the Fund’s (and other Oppenheimer funds’) financial, accounting, regulatory and investment matters and has contributed to the Boards’ deliberations.

41 OPPENHEIMER ULTRA-SHORT DURATION FUND

TRUSTEES AND OFFICERS Unaudited / Continued



Beverly L. Hamilton, Trustee (since 2011) Year of Birth:1946		Trustee of Monterey Institute for International Studies (educational organization) (2000-2014); Board Member of Middlebury College (educational organization) (December 2005-June 2011); Director of the Board (1991-2016), Vice Chairman of the Board (2006-2009) and Chairman of the Board (2010-2013) of American Funds’ Emerging Markets Growth Fund, Inc. (mutual fund); Director of The California Endowment (philanthropic organization) (April 2002-April 2008); Director (February 2002-2005) and Chairman of Trustees (2006-2007) of the Community Hospital of Monterey Peninsula; President of ARCO Investment Management Company (February 1991-April 2000); Member of the investment committees of The Rockefeller Foundation (2001-2006) and The University of Michigan (since 2000); Advisor at Credit Suisse First Boston’s Sprout venture capital unit (venture capital fund) (1994-January 2005); Trustee of MassMutual Institutional Funds (investment company) (1996-June 2004); Trustee of MML Series Investment Fund (investment company) (April 1989-June 2004); Member of the investment committee of Hartford Hospital (2000-2003); and Advisor to Unilever (Holland) pension fund (2000-2003). Ms. Hamilton has served on the Boards of certain Oppenheimer funds since 2002, during which time she has become familiar with the Fund’s (and other Oppenheimer funds’) financial, accounting, regulatory and investment matters and has contributed to the Boards’ deliberations.

Victoria J. Herget, Trustee (since 2012) Year of Birth: 1951		Board Chair (2008-2015) and Director (2004-Present) of United Educators (insurance company); Trustee (since 2000) and Chair (2010-2017) of Newberry Library (independent research library); Trustee, Mather LifeWays (senior living organization) (since 2001); Independent Director of the First American Funds (mutual fund family) (2003-2011); former Managing Director (1993-2001), Principal (1985-1993), Vice President (1978-1985) and Assistant Vice President (1973-1978) of Zurich Scudder Investments (investment adviser) (and its predecessor firms); Trustee (1992-2007), Chair of the Board of Trustees (1999- 2007), Investment Committee Chair (1994-1999) and Investment Committee member (2007-2010) of Wellesley College; Trustee, BoardSource (non-profit organization) (2006-2009) and Chicago City Day School (K-8 School) (1994- 2005). Ms. Herget has served on the Boards of certain Oppenheimer funds since 2012, during which time she has become familiar with the Fund’s (and other Oppenheimer funds’) financial, accounting, regulatory and investment matters and has contributed to the Boards’ deliberations.

Karen L. Stuckey, Trustee (since 2012) Year of Birth: 1953		Member (since May 2015) of Desert Mountain Community Foundation Advisory Board (non-profit organization); Partner (1990-2012) of PricewaterhouseCoopers LLP (professional services firm) (held various positions 1975-1990); Trustee (1992-2006); member of Executive, Nominating and Audit Committees and Chair of Finance Committee (1992-2006), and Emeritus Trustee (since 2006) of Lehigh University; member, Women’s Investment Management Forum (professional organization) (since inception) and Trustee of Jennies School for Little Children (non-profit) (2011-2014). Ms. Stuckey has served on the Boards of certain Oppenheimer funds since 2012, during which time she has become familiar with the Fund’s (and other Oppenheimer funds’) financial, accounting, regulatory and investment matters and has contributed to the Boards’ deliberations.

42 OPPENHEIMER ULTRA-SHORT DURATION FUND


James D. Vaughn, Trustee (since 2012) Year of Birth: 1945		Retired; former managing partner (1994-2001) of Denver office of Deloitte & Touche LLP, (held various positions in Denver and New York offices from 1969- 1993); Trustee and Chairman of the Audit Committee of Schroder Funds (2003- 2012); Board member and Chairman of Audit Committee of AMG National Trust Bank (since 2005); Trustee and Investment Committee member, University of South Dakota Foundation (since 1996); Board member, Audit Committee Member and past Board Chair, Junior Achievement (since 1993); former Board member, Mile High United Way, Boys and Girls Clubs, Boy Scouts, Colorado Business Committee for the Arts, Economic Club of Colorado and Metro Denver Network. Mr. Vaughn has served on the Boards of certain Oppenheimer funds since 2012, during which time he has become familiar with the Fund’s (and other Oppenheimer funds’) financial, accounting, regulatory and investment matters and has contributed to the Boards’ deliberations.
INTERESTED TRUSTEE AND OFFICER		Mr. Steinmetz is an “Interested Trustee” because he is affiliated with the Manager and the Sub-Adviser by virtue of his positions as Chairman of the Sub-Adviser and officer and director of the Manager. Both as a Trustee and as an officer, Mr. Steinmetz serves for an indefinite term, or until his resignation, retirement, death or removal. Mr. Steinmetz’s address is 225 Liberty Street, New York, New York 10281-1008. Mr. Steinmetz is an officer of 104 portfolios in the OppenheimerFunds complex.

Arthur P. Steinmetz, Trustee (since 2015), President and Principal Executive Officer (since 2014) Year of Birth: 1958		Chairman of OppenheimerFunds, Inc. (since January 2015); CEO and Chairman of OFI Global Asset Management, Inc. (since July 2014), President of OFI Global Asset Management, Inc. (since May 2013), a Director of OFI Global Asset Management, Inc. (since January 2013), Director of OppenheimerFunds, Inc. (since July 2014), President, Management Director and CEO of Oppenheimer Acquisition Corp. (OppenheimerFunds, Inc.‘s parent holding company) (since July 2014), and President and Director of OFI SteelPath, Inc. (since January 2013). Chief Investment Officer of the OppenheimerFunds advisory entities from (January 2013-December 2013); Executive Vice President of OFI Global Asset Management, Inc. (January 2013-May 2013); Chief Investment Officer of OppenheimerFunds, Inc. (October 2010-December 2012); Chief Investment Officer, Fixed-Income, of OppenheimerFunds, Inc. (April 2009-October 2010); Executive Vice President of OppenheimerFunds, Inc. (October 2009-December 2012); Director of Fixed Income of OppenheimerFunds, Inc. (January 2009-April 2009); and a Senior Vice President of OppenheimerFunds, Inc. (March 1993-September 2009).
OTHER OFFICERS OF THE FUND		The addresses of the Officers in the chart below are as follows: for Mss. Lo Bessette, Foxson and Picciotto, 225 Liberty Street, New York, New York 10281-1008, for Messrs. Proctor, Wilde and Petersen, 6803 S. Tucson Way, Centennial, Colorado 80112-3924. Each Officer serves for an indefinite term or until his or her resignation, retirement, death or removal.

Christopher Proctor, Vice President (since 2011) Year of Birth: 1968		Head of the Cash Strategies Team (since July 2013); Senior Vice President of the Sub-Adviser (since July 2013) and Senior Portfolio Manager of the Sub-Adviser (since January 2010). Vice President of the Sub-Adviser (August 2008-July 2013). Vice President at Calamos Asset Management (January 2007-March 2008) and Scudder-Kemper Investments (1999-2002). Managing Director and Co-Founder of Elmhurst Capital Management (June 2004-January 2007); Senior Manager of Research for Etrade Global Asset Management (2002-2004).

43 OPPENHEIMER ULTRA-SHORT DURATION FUND

TRUSTEES AND OFFICERS Unaudited / Continued


Adam S. Wilde, Vice President (since 2013) Year of Birth: 1978		Vice President of the Sub-Adviser (since May 2011) and a Portfolio Manager of the Sub-Adviser (since July 2013). He served as the head of credit research for the cash strategies team of the Sub-Adviser (from 2011 to 2013), and as an Assistant Vice President and senior research analyst of the Sub-Adviser (from 2008 to 2011). Mr. Wilde served as an intermediate research analyst of the Sub-Adviser (from 2007 to 2008) and served in other analyst roles of the Sub-Adviser (since 2002). Mr. Wilde joined the Sub-Adviser in 2001.

Cynthia Lo Bessette, Secretary and Chief Legal Officer (since 2016) Year of Birth: 1969		Executive Vice President, General Counsel and Secretary of OFI Global Asset Management, Inc. (since February 2016); Senior Vice President and Deputy General Counsel of OFI Global Asset Management, Inc. (March 2015-February 2016); Chief Legal Officer of OppenheimerFunds, Inc. and OppenheimerFunds Distributor, Inc. (since February 2016); Vice President, General Counsel and Secretary of Oppenheimer Acquisition Corp. (since February 2016); General Counsel of OFI SteelPath, Inc., OFI Advisors, LLC and Index Management Solutions, LLC (since February 2016); Chief Legal Officer of OFI Global Institutional, Inc., HarbourView Asset Management Corporation, OFI Global Trust Company, Oppenheimer Real Asset Management, Inc., OFI Private Investments Inc., Shareholder Services, Inc. and Trinity Investment Management Corporation (since February 2016); Corporate Counsel (February 2012-March 2015) and Deputy Chief Legal Officer (April 2013-March 2015) of Jennison Associates LLC; Assistant General Counsel (April 2008-September 2009) and Deputy General Counsel (October 2009-February 2012) of Lord Abbett & Co. LLC.

Jennifer Foxson, Vice President and Chief Business Officer (since 2014) Year of Birth: 1969		Senior Vice President of OppenheimerFunds Distributor, Inc. (since June 2014); Vice President of OppenheimerFunds Distributor, Inc. (April 2006-June 2014); Vice President of OppenheimerFunds, Inc. (January 1998-March 2006); Assistant Vice President of OppenheimerFunds, Inc. (October 1991-December 1998).

Mary Ann Picciotto, Chief Compliance Officer and Chief Anti-Money Laundering Officer (since 2014) Year of Birth: 1973		Senior Vice President and Chief Compliance Officer of OFI Global Asset Management, Inc. (since March 2014); Chief Compliance Officer of OppenheimerFunds, Inc., OFI SteelPath, Inc., OFI Global Institutional, Inc., Oppenheimer Real Asset Management, Inc., OFI Private Investments Inc., Harborview Asset Management Corporation, Trinity Investment Management Corporation, and Shareholder Services, Inc. (since March 2014); Managing Director of Morgan Stanley Investment Management Inc. and certain of its various affiliated entities; Chief Compliance Officer of various Morgan Stanley Funds (May 2010-January 2014); Chief Compliance Officer of Morgan Stanley Investment Management Inc. (April 2007-January 2014).

Brian S. Petersen, Treasurer and Principal Financial & Accounting Officer (since 2016) Year of Birth: 1970		Senior Vice President of OFI Global Asset Management, Inc. (since January 2017); Vice President of OFI Global Asset Management, Inc. (January 2013-January 2017); Vice President of OppenheimerFunds, Inc. (February 2007-December 2012); Assistant Vice President of OppenheimerFunds, Inc. (August 2002-2007).

The Fund’s Statement of Additional Information contains additional information about the Fund’s Trustees and Officers and is available without charge upon request, by calling 1.800.CALL OPP (225.5677).

44 OPPENHEIMER ULTRA-SHORT DURATION FUND

OPPENHEIMER ULTRA-SHORT DURATION FUND


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

45 OPPENHEIMER ULTRA-SHORT DURATION FUND

PRIVACY NOTICE

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 non-public 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.

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

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Your transactions with us, our affiliates or others.

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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 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.

46 OPPENHEIMER ULTRA-SHORT DURATION 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 conducted via our websites, including redemptions, exchanges and purchases, are secured by the highest encryption standards available. SSL is used to establish a secure connection between your PC and OppenheimerFunds’ server. It transmits information in an encrypted and scrambled format.

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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.

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You can exit the secure area by 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. Strengthening your online credentials–your online security profile–typically your user name, password, and security questions and answers, can be one of your most important lines of defense on the Internet. For additional information on how you can help prevent identity theft, visit https://www.oppenheimerfunds.com/security.

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 as of November 2017. 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, email us by clicking on the Contact Us section of our website at oppenheimerfunds.com, write to us at P.O. Box 5270, Denver, CO 80217-5270, or call us at 800 CALL OPP (225 5677).

47 OPPENHEIMER ULTRA-SHORT DURATION 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 © 2018 OppenheimerFunds Distributor, Inc. All rights reserved. RA1740.001.0718 September 26, 2018

Item 2. Code of Ethics.

The registrant has adopted a code of ethics that applies to the registrant’s principal executive officer, principal financial officer, principal accounting officer or controller or persons performing similar functions.

Item 3. Audit Committee Financial Expert.

The Board of Trustees of the registrant has determined that Karen L. Stuckey, the Chairwoman of the Board’s Audit Committee, is the audit committee financial expert and that Ms. Stuckey is “independent” for purposes of this Item 3.

Item 4. Principal Accountant Fees and Services.

(a)	Audit Fees

The principal accountant for the audit of the registrant’s annual financial statements billed $41,500 in fiscal 2018 and $40,600 in fiscal 2017.

(b)	Audit-Related Fees

The principal accountant for the audit of the registrant’s annual financial statements billed $3,500 in fiscal 2018 and $7,000 in fiscal 2017.

The principal accountant for the audit of the registrant’s annual financial statements billed $343,361 in fiscal 2018 and $320,775 in fiscal 2017 to the registrant’s investment adviser or any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant.

Such services include: Internal control reviews, GIPS attestation procedures, custody audits, CP Conduit fees, incremental, and additional, audit services.

(c)

Tax Fees

The principal accountant for the audit of the registrant’s annual financial statements billed no such fees in fiscal 2018 and no such fees in fiscal 2017.

The principal accountant for the audit of the registrant’s annual financial statements billed $533,392 in fiscal 2018 and $710,577 in fiscal 2017 to the registrant’s investment adviser or any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant.

Such services include: tax compliance, tax planning and tax advice. Tax compliance generally involves preparation of original and amended tax returns, claims for a refund and tax payment-planning services. Tax planning and tax advice includes assistance with tax audits and appeals, tax advice related to mergers and acquisitions and requests for rulings or technical advice from taxing authorities.

(d)	All Other Fees

The principal accountant for the audit of the registrant’s annual financial statements billed no such fees in fiscal 2018 and no such fees in fiscal 2017.

The principal accountant for the audit of the registrant’s annual financial statements billed no such fees in fiscal 2018 and no such fees in fiscal 2017 to the registrant’s investment adviser or any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant.

Such fees would include the cost to the principal accountant of attending audit committee meetings and consultations regarding the registrant’s retirement plan with respect to its Trustees.

(e)	(1) During its regularly scheduled periodic meetings, the registrant’s audit committee will pre-approve all audit, audit-related, tax and other services to be provided by the principal accountants of the registrant.

The audit committee has delegated pre-approval authority to its Chairman for any subsequent new engagements that arise between regularly scheduled meeting dates provided that any fees such pre-approved are presented to the audit committee at its next regularly scheduled meeting.

Under applicable laws, pre-approval of non-audit services may be waived provided that: 1) the aggregate amount of all such services provided constitutes no more than five percent of the total amount of fees paid by the registrant to its principal accountant during the fiscal year in which services are provided 2) such services were not recognized by the registrant at the time of engagement as non-audit services and 3) such services are promptly brought to the attention of the audit committee of the registrant and approved prior to the completion of the audit.

(2) 0%

(f)	Not applicable as less than 50%.

(g)

The principal accountant for the audit of the registrant’s annual financial statements billed $880,253 in fiscal 2018 and $1,038,352 in fiscal 2017 to the registrant and the registrant’s investment adviser or any entity controlling, controlled by, or under common control with the adviser that provides ongoing services to the registrant related to non-audit fees. Those billings did not include any prohibited non-audit services as defined by the Securities Exchange Act of 1934.

(h)

The registrant’s audit committee of the board of Trustees has considered whether the provision of non-audit services that were rendered to the registrant’s investment adviser, and any entity controlling, controlled by, or under common control with the investment adviser that provides ongoing services to the registrant that were not pre-approved pursuant to paragraph (c)(7)(ii) of Rule 2-01 of Regulation S-X is compatible with maintaining the principal accountant’s independence. No such services were rendered.

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 7/31/2018, 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. Disclosure of Securities Lending Activities for Closed-End Management Investment Companies.

Not applicable.

Item 13. Exhibits.

(a)	(1) Exhibit attached hereto.

(2) Exhibits 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 Ultra-Short Duration Fund


By:		/s/ Arthur P. Steinmetz
		Arthur P. Steinmetz
		Principal Executive Officer
Date: 9/21/2018

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: 9/21/2018


By:		/s/ Brian S. Petersen
		Brian S. Petersen
		Principal Financial Officer
Date: 9/21/2018

Expense Ratios