Strategy. Seeking to achieve its investment objective by pursuing a strategy intended to capture the persistence of price trends (up and/or down) observed across equity, fixed income, currency and commodity markets. The fund's investment strategy utilizes a combination of equity, fixed income, currency and commodity derivatives, as well as certain direct investments, to provide exposure to these markets and price trends. Trend following strategies attempt to capture trends in price movements in the markets they allocate to, generally taking long positions when prices move upwards, and taking short positions when they move downwards. The Adviser may also utilize non-trend factor strategies, which focus on quantitative analysis of fundamental, non-price data (e.g., carry, volatility) to achieve the fund's investment objective. Executing the … Show more… Seeking to achieve its investment objective by pursuing a strategy intended to capture the persistence of price trends (up and/or down) observed across equity, fixed income, currency and commodity markets. The fund's investment strategy utilizes a combination of equity, fixed income, currency and commodity derivatives, as well as certain direct investments, to provide exposure to these markets and price trends. Trend following strategies attempt to capture trends in price movements in the markets they allocate to, generally taking long positions when prices move upwards, and taking short positions when they move downwards. The Adviser may also utilize non-trend factor strategies, which focus on quantitative analysis of fundamental, non-price data (e.g., carry, volatility) to achieve the fund's investment objective. Executing the fund's strategy through investments in derivative instruments that may have a leveraging effect on the fund, including futures (such as equity index futures, commodity futures, and currency futures), options on futures, options, swaps (including excess return swaps and total return swaps) and other derivative instruments. The fund may have long/short exposure via these instruments. In addition to creating and/or adjusting the fund's investment exposure, the fund's strategy may also be used to enhance total return, to hedge risks, to manage certain investment risk, and/or to manage volatility. Employing various proprietary quantitative measures and qualitative techniques to evaluate price trends and non-trend factors across the asset classes in which the fund invests. The fund's quantitative measures are developed and maintained by the Adviser and are subject to change over time without notice in the Adviser's discretion. The Adviser retains discretion over the target asset allocations, which may include positions that differ from the target allocations indicated by the quantitative measures. Investing up to 25% of assets in Fidelity SAI Managed Futures Cayman Ltd., a wholly-owned subsidiary organized under the laws of the Cayman Islands that invests in commodity-linked derivatives and related collateral (cash or cash equivalent investments, short-term investment funds and/or U.S. Government securities), commodity-related exchange-traded funds (ETFs), and commodity-related exchange-traded notes (ETNs). Investing a significant portion of the fund's assets in U.S. Government securities, short-term investment funds, cash, and cash equivalents for investment purposes and to maintain collateral to cover derivatives positions. Show less