UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED
MANAGEMENT INVESTMENT COMPANIES

Form N-CSR is to be used by management investment companies to file reports with the Commission not later than 10 days after the transmission to stockholders of any report that is required to be transmitted to stockholders under Rule 30e-1 under the Investment Company Act of 1940 (17 CFR 270.30e-1). The Commission may use the information provided on Form N-CSR in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-CSR, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-CSR unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. SS. 3507.

ITEM 1. REPORTS TO STOCKHOLDERS.

Closed-End Funds

Nuveen Investments

Closed-End Funds

Seeks Attractive Distribution and Return Potential from a Portfolio
Consisting Primarily of Mortgage-Backed Securities

Semi-Annual Report

June 30, 2013

Nuveen Mortgage Opportunity Term Fund

JLS

Nuveen Mortgage Opportunity Term Fund 2

JMT

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Table of Contents

Letter to Shareholders

Dear Shareholders,

After nine years of serving as lead director and independent chairman of the Nuveen Fund Board, my term of office has come to an end as of June 30, 2013. It has been a privilege to use this space to communicate with you on some of the broad economic trends in the U.S. and abroad and how they are impacting the investment environment in which your funds operate. In addition, I have enjoyed offering some perspective on how your Board views the various Nuveen investment teams as they apply their investment disciplines in that investment environment.

My term has coincided with a particularly challenging period for both mutual fund sponsors and investors. Since 2000 there have been three periods of unusually strong stock market growth and two major market declines. Recent years have been characterized by a search for yield in fixed income securities to compensate for an extended period of very low interest rates. Funds are investing more in foreign and emerging markets that require extensive research capabilities to overcome the more limited transparency and higher volatility in those markets. New fund concepts often incorporate derivative financial instruments that offer efficient ways to hedge investment risk or gain exposure to selected markets. Fund trading teams operate in many new domestic and international venues with quite different characteristics. Electronic trading and global communication networks mean that fund managers must be able to thrive in financial markets that react instantaneously to newsworthy events and are more interconnected than ever.

Nuveen has committed additional resources to respond to these changes in the fund industry environment. It has added IT and research resources to assemble and evaluate the increased flow of detailed information on economies, markets and individual companies. Based on its experience during the financial crisis of 2008-09, Nuveen has expanded its resources dedicated to valuing and trading portfolio securities with a particular focus on stressed financial market conditions. It has added systems and experienced risk management professionals to work with investment teams to better help evaluate whether their funds' risk exposures are appropriate in view of the return targets. The investment teams have also reflected on recent experience to reaffirm or modify their investment disciplines. Finally, experienced professionals and IT resources have been added to address new regulatory requirements designed to better inform and protect investors. The Nuveen Fund Board has enthusiastically encouraged these initiatives.

The Board has always viewed itself as your representatives to assure that Nuveen brings together experienced people, proven technologies and effective processes designed to produce results that meet investor expectations. It is important to note that our activities are highlighted by the annual contract renewal process. Despite its somewhat formal language, I strongly encourage you to read the summary because it offers an insight into our oversight process. The report is included in the back of this shareholder report. The renewal process is very comprehensive and includes a number of evaluations and discussions between the Board and Nuveen during the year. The summary also describes what has been achieved across the Nuveen fund complex and at individual funds such as yours.

As I leave the chairmanship and resume my role as a member of the Board, please be assured that I and my fellow Board members will continue to hold your interests uppermost in our minds as we oversee the management of your funds and that we greatly appreciate your confidence in your Nuveen fund.

Very sincerely,

Robert P. Bremner
August 22, 2013

Portfolio Manager's Comments

Nuveen Mortgage Opportunity Term Fund (JLS)
Nuveen Mortgage Opportunity Term Fund 2 (JMT)

The investment adviser for both Funds is Nuveen Fund Advisors, LLC (NFA), an affiliate of Nuveen Investments. NFA is responsible for determining each Fund's overall investment strategy and monitoring the performance of Wellington Management Company, LLP (Wellington Management), the sub-adviser for both Funds.

Wellington Management is responsible for implementing each Fund's direct investments in mortgage-backed securities and other permitted investments. Michael Garrett serves as portfolio manager for these Funds.

Here Michael talks about his management strategy and the performance of the Funds for the six-month period ended June 30, 2013.

What strategies were used to manage the Funds during this six-month reporting period ended June 30, 2013?

Both Funds seek to generate total returns by investing in a diverse portfolio of mortgage-backed securities (MBS), consisting primarily of non-agency residential mortgage-backed securities (RMBS) and commercial mortgage-backed securities (CMBS). Under normal circumstances, both Funds will invest at least 80% of their managed assets in MBS, primarily non-agency RMBS and CMBS. Both JLS and JMT may be leveraged directly to a maximum effective leverage of 33% of total net asset value. The Funds have a limited term of 10 years from each Fund's inception, at which time all net asset value will be distributed to shareholders of record.

During the reporting period, we remained constructive on CMBS, but continued to believe that the non-agency RMBS sector offered better relative value and we positioned the Funds accordingly. The Funds continue to be conservatively positioned within RMBS, with a bias toward higher quality collateral to try to protect against downside risk in the event of a prolonged path toward economic recovery.

CMBS performance continued to be highly correlated with the broader credit markets during the reporting period. The first quarter of 2013 began on a positive note with increased clarity on the U.S. "fiscal cliff" situation and the sector had modestly positive returns. The credit curve flattened over the period with the lower quality issues outperforming their higher quality counterparts. However, during the second quarter of 2013, CMBS lost ground due to fears of a less accommodative Federal Reserve. The markets entered into a sell-off mode that was more pronounced in the more liquid, higher quality segments of the sector, driven by investors' need for liquidity. As per Moody's CPPI, Commercial Real Estate (CRE) valuations are up 35% from January 2010 lows and stand only about 20% off 2007 peaks, on an

Certain statements in this report are forward-looking statements. Discussions of specific investments are for illustration only and are not intended as recommendations of individual investments. The forward-looking statements and other views expressed herein are those of the portfolio manager as of the date of this report. Actual future results or occurrences may differ significantly from those anticipated in any forward-looking statements and the views expressed herein are subject to change at any time, due to numerous market and other factors. The Funds disclaim any obligation to update publicly or revise any forward-looking statements or views expressed herein.

Ratings shown are the highest rating given by one of the following national rating agencies: Standard & Poor's, Moody's Investors Service, Inc. or Fitch, Inc. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below investment grade ratings. Certain bonds backed by U.S. Government or agency securities are regarded as having an implied rating equal to the rating of such securities. Holdings designated N/R are not rated by these national rating agencies.

aggregate level. Collateral performance is stabilizing, but the CRE recovery continues to be divided, where the institutional quality properties have seen a strong recovery and the non-major markets, in contrast, continues to be sluggish.

The non-agency RMBS market rallied to start the year as the sector continued to benefit from positive home price momentum and broad based investor demand amid low market yields. However, the sell-off in rates and risk assets after the Federal Open Market Committee (FOMC) comments in the second quarter caused residential credit markets to experience significant and broad price weakness. This meaningful underperformance erased year-to-date gains for higher quality non-agency RMBS despite improving fundamentals and negative net new issuance. From a fundamental perspective, housing data continued to be supportive with 15 consecutive months of home-price appreciation. According to CoreLogic, home prices nationwide rose 12.2% in May 2013 (most recent data available at the time this report was prepared), on a year-over-year basis , the largest such gain since February 2006.

The technically driven spread widening in the second quarter provided buying opportunities in the residential and commercial sectors for the Funds. We maintained a constructive outlook for non-agency RMBS and believe it is positioned to perform well relative to competing fixed income sectors.

At the beginning of the reporting period, each Fund remained invested, through separate feeder funds, in a master fund (Master PPIP Fund) managed by Wellington Management that invests directly in MBS and other assets eligible for purchase under the Public-Private Investment Program (PPIP) established by the U.S. Department of the Treasury. During the reporting period, the Master PPIP Fund's investments were liquidated, its leverage was repaid and the remaining proceeds were returned to investors, including the Funds, in accordance with the terms of the PPIP program. Income and proceeds received by each Fund as part of this managed wind down have been invested directly in MBS and other permitted investments in accordance with each Fund's investment objectives. In addition, the Funds' leverage obtained through its indirect investment in the Master PPIP Fund has been replaced with other leverage arrangements directly at the Fund level. Such other direct forms of leverage include the use of reverse repurchase agreements, which the Funds employed during the reporting period.

How did the Funds perform during this six-month reporting period ended June 30, 2013?

The tables in the Performance Overview and Holding Summaries section of this report provide total return performance for the Funds for the six-month, one-year and since inception periods ended June 30, 2013. For the six-month reporting period, the Funds' share at net asset value (NAV) outperformed the Barclays U.S. Aggregate Bond Index. This index reflects the general performance of the bond market over these periods, but not the specific MBS market in which the Funds invest. On the whole, the performance of the MBS market was mixed during this reporting period.

The Funds' allocation to the U.S. Treasury PPIP program was a primary contributor to returns during the first half of the reporting period. The Funds' exposure to residential credit, particularly the higher quality sectors (Prime and Alt-A), posted positive absolute total returns. The Funds' allocation to the commercial sector negatively impacted returns over the period, driven primarily by the exposure to new issue and multi-family CMBS. The Funds' exposure to agency collateralized mortgage obligations (CMOs) was a negative contributor to performance. Volatility resurfaced in the later half of the second quarter, as market participants broadly were surprised with the unexpected hawkish tone coming from the statements by Federal Reserve policymakers. Despite the recent underperformance, the momentum of home price appreciation and the negative net new issuance continues to support the performance of the underlying mortgages in the residential sector. With an emphasis on the long-term, we continued to focus on finding opportunities to add securities we feel were best positioned to provide stability of principal and attractive income over the duration of the Funds' limited terms.

The Funds also utilized U.S. Treasury futures to hedge against rises in interest rates and utilized interest rate swap contracts for duration management purposes during the reporting period. These positions had a modest positive impact on performance during the reporting period.

Fund Leverage

IMPACT OF THE FUNDS' LEVERAGE STRATEGIES ON PERFORMANCE

As discussed previously, one important factor impacting the return of the Funds relative to their benchmarks was the Funds' use of financial leverage through their investments in the Master PPIP Funds and reverse repurchase agreements. The Funds use leverage because their managers believe that, over time, leveraging provides opportunities for additional income and total return for common shareholders. However, use of leverage also can expose common shareholders to additional volatility. For example, as the prices of securities held by the Funds decline, the negative impact of these valuation changes on common share net asset value and common shareholder total return is magnified by the use of leverage. Conversely, leverage may enhance common share returns during periods when the prices of securities held by the Funds generally are rising. Leverage had a positive impact on the performance of the Funds over this reporting period.

THE FUNDS' EFFECTIVE LEVERAGE

During the period, the Funds employed leverage through the Master PPIP Fund and reverse repurchase agreements. As noted previously, the Master PPIP Fund was wound down during the reporting period. As of June 30, 2013, the values of the Funds' reverse repurchase agreements are as shown in the accompanying table.

Refer to Notes to Financial Statements, Footnote 3—Portfolio Securities and Investments in Derivatives for further details.

As of June 30, 2013, the Funds' percentages of leverage are shown in the accompanying table.

*  Effective leverage is a Fund's effective economic leverage, and includes the leverage effects of certain derivative and other investments in a Fund's portfolio that increase the Fund's investment exposure.

Share Information

Distribution Information

The following information regarding each Fund's distributions is current as of June 30, 2013. Each Fund's distribution levels may vary over time based on each Fund's investment activities and portfolio investment value changes.

During the current reporting period, the Funds' monthly dividends to shareholders were as shown in the accompanying table.

*  Current Distribution Rate is based on each Fund's current annualized monthly distribution divided by the Fund's current market price. Each Fund's monthly distributions to its shareholders may be comprised of ordinary income, net realized capital gains and, if at the end of the fiscal year the Fund's cumulative net ordinary income and net realized gains are less than the amount of the Fund's distributions, a return of capital for tax purposes.

The Funds employ effective leverage through the use of reverse repurchase agreements. Effective leverage provides the potential for higher earnings (net investment income), total returns and distributions over time, but, as noted earlier, also increases the variability of shareholders' net asset value per share in response to changing market conditions.

During the current fiscal period, each Fund adopted a managed distribution program. The goal of this program is to provide shareholders with relatively consistent and predictable cash flow by systematically converting the Fund's cash flows from investment strategies. As a result, regular distributions throughout the year are likely to include a portion of expected long-term gains (both realized and unrealized), along with net investment income.

Important points to understand about the managed distribution program are:

•  Each Fund seeks to establish a distribution rate that roughly corresponds to the cash flows from its investment strategy. However, you should not draw any conclusions about a Fund's past or future investment performance from its current distribution rate.

•  Actual returns will differ from cash flows (and therefore a Fund's distribution rate), at least over shorter time periods. Over a specific timeframe, the difference between actual returns and total distributions will be reflected in an increasing (returns exceed distributions) or a decreasing (distributions exceed returns) Fund net asset value.

•  Each distribution is expected to be paid from some or all of the following sources:

•  net investment income (regular interest and dividends),

•  realized capital gains, and

•  unrealized gains, or, in certain cases, a return of principal (non-taxable distributions).

•  A non-taxable distribution is a payment of a portion of a Fund's capital. When a Fund's returns exceed distributions, it may represent portfolio gains generated, but not realized as a taxable capital gain. In periods when a Fund's returns fall short of distributions, the shortfall will represent a portion of your original principal, unless the shortfall is offset during other time periods over the life of your investment (previous or subsequent) when a Fund's total return exceeds distributions.

•  Because distribution source estimates are updated during the year based on a Fund's performance and forecast for its current fiscal year (which is the calendar year for each Fund), estimates on the nature of your distributions provided at the time the distributions are paid may differ from both the tax information reported to you in your Fund's IRS Form 1099 statement provided at year end, as well as the ultimate economic sources of distributions over the life of your investment.

The following table provides estimated information regarding each Fund's distributions and total return performance for the six months ended June 30, 2013. This information is provided on a tax basis rather than a generally accepted accounting principles (GAAP) basis. This information is intended to help you better understand whether the Funds' returns for the specified time period were sufficient to meet their distributions.

Share Repurchases

Since the inception of the Funds' repurchase programs, the Funds have not repurchased any of their outstanding shares.

Other Share Information

As of June 30, 2013, and during the six-month reporting period, the Funds' share prices were trading at a premium/(discount) to their NAVs as shown in the accompanying table.

Risk Considerations

Fund shares are not guaranteed or endorsed by any bank or other insured depository institution, and are not federally insured by the Federal Deposit Insurance Corporation. Shares of closed-end funds are subject to investment risks, including the possible loss of principal invested. Past performance is no guarantee of future results. Fund common shares are subject to a variety of risks, including:

Investment, Market and Price Risk. An investment in common shares is subject to investment risk, including the possible loss of the entire principal amount that you invest. Your investment in common shares represents an indirect investment in the corporate securities owned by the Funds, which generally trade in the over-the-counter markets. Shares of closed-end investment companies like the Funds frequently trade at a discount to their NAV. Your common shares at any point in time may be worth less than your original investment, even after taking into account the reinvestment of Fund dividends and distributions.

Leverage Risk. A Fund's use of leverage creates the possibility of higher volatility for the Fund's per share NAV, market price, and distributions. Leverage risk can be introduced through regulatory leverage (issuing preferred shares or debt borrowings at the Fund level) or through certain derivative investments held in a Fund's portfolio. Leverage typically magnifies the total return of a Fund's portfolio, whether that return is positive or negative. The use of leverage creates an opportunity for increased common share net income, but there is no assurance that a Fund's leveraging strategy will be successful.

Tax Risk. The tax treatment of Fund distributions may be affected by new IRS interpretations of the Internal Revenue Code and future changes in tax laws and regulations.

Issuer Credit Risk. This is the risk that a security in a Fund's portfolio will fail to make dividend or interest payments when due.

Call Risk or Prepayment Risk. Issuers may exercise their option to prepay principal earlier than scheduled, forcing a Fund to reinvest in lower-yielding securities.

Interest Rate Risk. Fixed-income securities such as bonds, preferred, convertible and other debt securities will decline in value if market interest rates rise.

Below-Investment Grade Risk. Investments in securities below investment grade quality are predominantly speculative and subject to greater volatility and risk of default.

Mortgage-Backed Securities (MBS) Risk. Investing in MBS entails various risks, including credit risks inherent in the underlying collateral, the risk that the servicer fails to perform its duties, liquidity risks, interest rate risks, structure risks, and geographical concentration risks.

Limited Term Risk. It is anticipated that JLS will terminate on or before November 30, 2019 and JMT will terminate on or before February 28, 2020, although each could terminate sooner or later under certain conditions. Because the assets of the Funds will be liquidated in connection with their respective terminations, each may be required to sell portfolio securities when they otherwise would not desire to do so, including at times when market conditions are not favorable, which may cause them to lose money.

Reinvestment Risk. If market interest rates decline, income earned from a Fund's portfolio may be reinvested at rates below that of the original bond that generated the income.

Prepayment Risk. MBS represent an interest in a pool of mortgages. These mortgages typically permit borrowers to prepay amounts owing, often with no penalty. The relationship between borrower prepayments and changes in interest

rates may mean some high-yielding mortgage-related and asset-backed securities have less potential for increases in value if market interest rates were to fall than conventional bonds with comparable maturities. In addition, in periods of falling interest rates, the rate of prepayments tends to increase. During such periods, the reinvestment of prepayment proceeds by the Fund will generally be at lower rates than the rates that were carried by the obligations that have been prepaid. Because of these and other reasons, the total return and maturity of mortgagerelated and asset-backed securities may be difficult to predict precisely. To the extent that the Fund purchases mortgage-related securities at a premium, prepayments may result in loss of the Fund's principal investment to the extent of any unamortized premium.

Nuveen Mortgage Opportunity Term Fund (JLS)

Performance Overview and Holding Summaries as of June 30, 2013

Average Annual Total Returns as of June 30, 2013

Past performance is not predictive of future results. Current performance may be higher or lower than the data shown. Returns do not reflect the deduction of taxes that shareholders may have to pay on Fund distributions or upon the sale of Fund shares. Comparative index return information is provided for the Fund's shares at NAV only. Indexes are not available for direct investment.

Share Price Performance — Weekly Closing Price

Fund Allocation²

(as a % of net assets)

Refer to the Glossary of Terms Used in this Report for further definition of the terms used within this page.

1  Since inception returns are from 11/25/09.

2  Holdings are subject to change.

3  Other assets less liabilities.

Nuveen Mortgage Opportunity Term Fund 2 (JMT)

Performance Overview and Holding Summaries as of June 30, 2013

Average Annual Total Returns as of June 30, 2013

Past performance is not predictive of future results. Current performance may be higher or lower than the data shown. Returns do not reflect the deduction of taxes that shareholders may have to pay on Fund distributions or upon the sale of Fund shares. Comparative index return information is provided for the Fund's shares at NAV only. Indexes are not available for direct investment.

Share Price Performance — Weekly Closing Price

Fund Allocation²

(as a % of net assets)

Refer to the Glossary of Terms Used in this Report for further definition of the terms used within this page.

1  Since inception returns are from 2/23/10.

2  Holdings are subject to change.

3  Other assets less liabilities.

JLS

JMT

Shareholder Meeting Report

The annual meeting of shareholders was held in the offices of Nuveen Investments on April 3, 2013; at this meeting the shareholders were asked to vote on the election of Board Members.

JLS

Nuveen Mortgage Opportunity Term Fund

Portfolio of Investments

  June 30, 2013 (Unaudited)

JLS

Nuveen Mortgage Opportunity Term Fund (continued)

Portfolio of Investments June 30, 2013 (Unaudited)

JLS

Nuveen Mortgage Opportunity Term Fund (continued)

Portfolio of Investments June 30, 2013 (Unaudited)