v3.26.3
Investment Risks
Sep. 29, 2026
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | Risk Nondiversified Status [Member]  
Prospectus Line Items  
Risk [Text Block] In addition, the fund is classified as non-diversified under the Investment Company Act of 1940 (1940 Act), which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | InvestingInOtherFundsMember  
Prospectus Line Items  
Risk [Text Block] Investing in Other Funds. Regulatory restrictions may limit the amount that one fund can invest in another, which means that the fund's manager may not be able to invest as much as it wants to in some other funds. The fund bears all risks of investment strategies employed by the underlying funds, including the risk that the underlying funds will not meet their investment objectives.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | StockMarketVolatilityMember  
Prospectus Line Items  
Risk [Text Block] Stock Market Volatility. Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | SubsidiaryRiskMember  
Prospectus Line Items  
Risk [Text Block] Subsidiary Risk. Investment in Fidelity SAI Alternative Risk Premia Commodity Strategy Fund Cayman Ltd, an unregistered subsidiary, is not subject to the investor protections of the Investment Company Act of 1940 (1940 Act) and is subject to the risks associated with investing in derivatives and commodity-linked investing in general. Changes in tax and other laws could negatively affect investments in the subsidiary
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | CommodityFuturesMember  
Prospectus Line Items  
Risk [Text Block] Commodity Futures. Investments in commodity futures contracts are also subject to the risk of the failure of any of the exchanges on which the fund's positions trade or of its clearinghouses or counterparties. In addition, certain commodity exchanges limit fluctuations in certain futures contract prices during a single day by regulations referred to as "daily price fluctuation limits" or "daily limits." Under such daily limits, during a single trading day no trades may be executed at prices beyond the daily limit. If triggered, these limits could prevent the fund from liquidating unfavorable positions and subject the fund to losses or prevent it from entering into desired trades during the particular trading day.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | ShortSalesAndLeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Short Sales and Leverage Risk. Short sales pose more risk than long positions. Because a short position loses value as the security's price increases, the loss on a short sale is theoretically unlimited. Regulatory bans on certain short selling activities may prevent a fund from fully implementing its strategy. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. The fund's use of futures, forward contracts, options, swaps, and other derivative instruments may result in losses. The value of these derivative instruments may pose risks in addition to and greater than those associated with investing directly in securities, currencies or other instruments and may be illiquid or less liquid, volatile, difficult to price and leveraged so that small changes in the value of underlying instruments may produce disproportionate losses to the fund. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments. Moreover, a relatively small price movement in a derivative contract may result in substantial losses to the fund, exceeding the amount of the margin paid. The use of derivatives can increase the fund's risk exposure to underlying assets and their attendant risks, while also exposing the fund to the risk of mispricing or other improper valuation and the risk that changes in the value of a derivative may not correlate as anticipated with the underlying asset, rate, index or overall securities markets, thereby reducing their effectiveness.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | CommodityLinkedInvestingMember  
Prospectus Line Items  
Risk [Text Block] Commodity-Linked Investing. The value of commodities and commodity-linked investments may be affected by the performance of the overall commodities markets as well as weather, political, tax, and other regulatory and market developments. Commodity-linked investments may be more volatile and less liquid than the underlying commodity, instruments, or measures.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | InvestingInEtfsAndEtnsMember  
Prospectus Line Items  
Risk [Text Block] Investing in ETFs and ETNs. ETFs and ETNs may trade in the secondary market at prices below the value of their underlying portfolios and may not be liquid. ETFs that track an index are subject to tracking error and may be unable to sell poorly performing assets that are included in their index or other benchmark. ETNs are subject to the risks associated with debt securities, including counterparty risk of the issuer.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | USGovernmentObligationsRiskMember  
Prospectus Line Items  
Risk [Text Block] U.S. Government Obligations Risk. Certain securities in which the fund may invest, including securities issued by certain U.S. Government agencies and U.S. Government sponsored enterprises, are not guaranteed by the U.S. Government or supported by the full faith and credit of the United States.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Commodity Strategy Fund | SwapsRiskMember  
Prospectus Line Items  
Risk [Text Block] Swaps Risk. The fund may invest in excess return and total return swaps. Swaps may be difficult to value and may be illiquid. The fund could experience losses if the underlying asset or reference does not perform as anticipated. Certain swaps have the potential for unlimited losses, regardless of the size of the initial investment.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | Risk Nondiversified Status [Member]  
Prospectus Line Items  
Risk [Text Block] In addition, the fund is classified as non-diversified under the Investment Company Act of 1940 (1940 Act), which means that it has the ability to invest a greater portion of assets in securities of a smaller number of individual issuers than a diversified fund. As a result, changes in the market value of a single investment could cause greater fluctuations in share price than would occur in a more diversified fund.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | Risk Lose Money [Member]  
Prospectus Line Items  
Risk [Text Block]   You could lose money by investing in the fund.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | Risk Not Insured Depository Institution [Member]  
Prospectus Line Items  
Risk [Text Block] An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency .
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | InvestingInOtherFundsMember  
Prospectus Line Items  
Risk [Text Block] Investing in Other Funds. Regulatory restrictions may limit the amount that one fund can invest in another, which means that the fund's manager may not be able to invest as much as it wants to in some other funds. The fund bears all risks of investment strategies employed by the underlying funds, including the risk that the underlying funds will not meet their investment objectives.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | IssuerSpecificChangesMember  
Prospectus Line Items  
Risk [Text Block] Issuer-Specific Changes. The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole. Changes in the financial condition of an issuer or counterparty (e.g., broker-dealer or other borrower in a securities lending transaction) can increase the risk of default by an issuer or counterparty, which can affect a security's or instrument's value or result in delays in recovering securities and/or capital from a counterparty.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | CurrencyExposureMember  
Prospectus Line Items  
Risk [Text Block] Currency Exposure. Because the fund is normally exposed to foreign currencies, it could experience losses based solely on the weakness of foreign currencies versus the U.S. dollar and changes in the exchange rates between foreign currencies and the U.S. dollar. Currency risk may be particularly high to the extent that a fund invests in foreign currencies or engages in foreign currency transactions that are economically tied to emerging markets countries. These emerging markets currency transactions may present market, credit, currency, liquidity, legal, political and other risks different from, or greater than, the risks of investing in developed foreign currencies or engaging in foreign currency transactions that are economically tied to developed foreign countries.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | InterestRateChangesMember  
Prospectus Line Items  
Risk [Text Block] Interest Rate Changes. Interest rate increases can cause the price of a debt security to decrease.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | ForeignCurrencyTransactionsMember  
Prospectus Line Items  
Risk [Text Block] Foreign Currency Transactions. The fund may enter into forward foreign currency exchange contracts for both hedging and non-hedging purposes. A forward foreign currency exchange contract, which involves an obligation to purchase or sell a specific currency at a future date at a price set at the time of the contract, reduces a fund's exposure to changes in the value of the currency it will deliver and increases its exposure to changes in the value of the currency it will receive for the duration of the contract. Foreign exchange rates can be extremely volatile and the degree of volatility of the market or in the direction of the market from that anticipated by the Adviser may result in losses to the fund.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | ShortSalesAndLeverageRiskMember  
Prospectus Line Items  
Risk [Text Block] Short Sales and Leverage Risk. Short sales pose more risk than long positions. Because a short position loses value as the security's price increases, the loss on a short sale is theoretically unlimited. Regulatory bans on certain short selling activities may prevent a fund from fully implementing its strategy. Leverage can increase market exposure, magnify investment risks, and cause losses to be realized more quickly. The fund's use of futures, forward contracts, options, swaps, and other derivative instruments may result in losses. The value of these derivative instruments may pose risks in addition to and greater than those associated with investing directly in securities, currencies or other instruments and may be illiquid or less liquid, volatile, difficult to price and leveraged so that small changes in the value of underlying instruments may produce disproportionate losses to the fund. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments. Moreover, a relatively small price movement in a derivative contract may result in substantial losses to the fund, exceeding the amount of the margin paid. The use of derivatives can increase the fund's risk exposure to underlying assets and their attendant risks, while also exposing the fund to the risk of mispricing or other improper valuation and the risk that changes in the value of a derivative may not correlate as anticipated with the underlying asset, rate, index or overall securities markets, thereby reducing their effectiveness.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | USGovernmentObligationsRiskMember  
Prospectus Line Items  
Risk [Text Block] U.S. Government Obligations Risk. Certain securities in which the fund may invest, including securities issued by certain U.S. Government agencies and U.S. Government sponsored enterprises, are not guaranteed by the U.S. Government or supported by the full faith and credit of the United States.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | SwapsRiskMember  
Prospectus Line Items  
Risk [Text Block] Swaps Risk. The fund may invest in excess return and total return swaps. Swaps may be difficult to value and may be illiquid. The fund could experience losses if the underlying asset or reference does not perform as anticipated. Certain swaps have the potential for unlimited losses, regardless of the size of the initial investment.
FidelitySAIAlternativeRiskPremiaCurrencyStrategyFund-PRO | Fidelity SAI Alternative Risk Premia Currency Strategy Fund | InvestingInExchangeTradedFundsEtfsAndEtnsMember  
Prospectus Line Items  
Risk [Text Block] Investing in Exchange Traded Funds (ETFs) and ETNs. ETFs and ETNs may trade in the secondary market at prices below the value of their underlying portfolios and may not be liquid. ETFs that track an index are subject to tracking error and may be unable to sell poorly performing assets that are included in their index or other benchmark. ETNs are subject to the risks associated with debt securities, including counterparty risk of the issuer.
Document Type 485BPOS