v3.25.4
Investment Risks - State Street Prime Money Market ETF
Feb. 05, 2026
Money Market Risk Floating NAV [Member]  
Prospectus [Line Items]  
Risk [Text Block] Money Market Risk-Floating NAV: The Fund does not maintain a constant net asset value per share. The Fund's net asset value is calculated to six decimal places for transactions with Authorized Participants and will vary reflecting the value of the portfolio of investments held by the Fund. The Fund's share price will be calculated to less decimal places in connection with transactions on the New York Stock Exchange LLC (the “Exchange”). It is possible to lose money by investing in the Fund.
Money Market Liquidity Fee Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Money Market Liquidity Fee Risk: The Board, or its delegate, must impose a mandatory liquidity fee upon all shares redeemed if the Fund's net redemptions on any business day exceed 5% of the Fund's net assets, unless the liquidity costs are de minimis. Accordingly, redemptions by Authorized Participants may be subject to a mandatory liquidity fee at certain times, which may impact the Fund's price on the Exchange. A potential liquidity fee, even if not imposed, may also impact the Fund's share price on the Exchange. Investors trading on the Exchange will not be directly subject to the mandatory liquidity fee. Additionally, the Board, or its delegate, has discretion to impose a liquidity fee of up to 2% upon the redemption of shares if the Board or its delegate determines that is in the best interest of the Fund. Accordingly, redemptions by Authorized Participants may be subject to a discretionary liquidity fee when an Authorized Participant redeems shares which may impact the Fund's price on the Exchange. A potential liquidity fee, even if not imposed, may also impact the Fund's share price on the Exchange. Investors trading on the Exchange will not be directly subject to the discretionary liquidity fee.
Liquidity Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Liquidity Risk: Lack of a ready market, stressed market conditions, or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price or at all. Illiquid investments may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. If the liquidity of the Fund's holdings deteriorates, it may lead to differences between the market price of Fund Shares and the NAV of Fund Shares and/or wider bid/ask spreads, and could result in the Fund Shares being less liquid. Illiquidity of the Fund's holdings may also limit the ability of the Fund to obtain cash to meet redemptions on a timely basis. In addition, the Fund, due to limitations on investments in any illiquid investments and/or the difficulty in purchasing and selling such investments, may be unable to achieve its desired level of exposure to a certain market or sector.
Credit Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Credit Risk: Credit risk is the risk that an issuer or counterparty will fail to pay its obligations to the Fund when they are due. As a result, the Fund's income might be reduced, the value of the Fund's investment might fall, and/or the Fund could lose the entire amount of its investment. Changes in the financial condition of an issuer or counterparty, changes in specific economic, social or political conditions that affect a particular type of security or other instrument or an issuer, and changes in economic, social or political conditions generally can increase the risk of default by an issuer or counterparty, which can affect a security's or other instrument's credit quality or value and an issuer's or counterparty's ability to pay interest and principal when due. The values of lower-quality debt securities, including floating rate loans, tend to be particularly sensitive to these changes. The values of securities also may decline for a number of other reasons that relate directly to the issuer, such as management performance, financial leverage and reduced demand for the issuer's goods and services, as well as the historical and prospective earnings of the issuer and the value of its assets.
Interest Rate Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Interest Rate Risk: Interest rate risk is the risk that debt securities will decline in value because of increases in interest rates. The value of a security with a longer duration will be more sensitive to changes in interest rates than a similar security with a shorter duration. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments.
Authorized Participants Market Makers and Liquidity Providers Concentration Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Authorized Participants, Market Makers and Liquidity Providers Concentration Risk: The Fund has a limited number of financial institutions that may act as Authorized Participants (“APs”) and there may be a limited number of market makers and/or liquidity providers in the marketplace. To the extent either of the following events occur, Fund Shares may trade at a material discount to NAV and possibly face delisting: (i) APs exit the business or otherwise become unable to process creation and/or redemption orders and no other APs step forward to perform these services, or (ii) market makers and/or liquidity providers exit the business or significantly reduce their business activities and no other entities step forward to perform their functions.
Banking Companies Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Banking Companies Risk: The performance of bank stocks may be affected by extensive governmental regulation, which may limit the amounts and types of loans and other financial commitments they can make, the interest rates and fees they can charge, and the amount of capital they must maintain. The impact of changes in regulations and capital requirements on a banking company cannot be predicted and may negatively impact such banking company. Profitability is largely dependent on the availability and cost of capital funds, and can fluctuate significantly when interest rates change. Credit losses resulting from financial difficulties of borrowers can negatively impact banking companies. Banks may also be subject to severe price competition. Competition among banking companies is high and failure to maintain or increase market share may result in lost market value.
Cash Transaction Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Cash Transaction Risk: The Fund may sell portfolio securities to meet some or all of a redemption request with cash. In such cases, the Fund may incur taxable gains or losses that it might not have incurred had it made redemptions entirely in-kind. As a result, the Fund may pay out higher annual capital gain distributions than if the in-kind redemption process was used.
Counterparty Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Counterparty Risk: The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate the transaction, and it may be delayed or prevented from realizing on any collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.
Debt Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Debt Securities Risk: The values of debt securities may increase or decrease as a result of the following: market fluctuations, changes in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments, or illiquidity in debt securities markets. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. During periods when interest rates are at low levels, the Fund's yield can be low, and the Fund may have a negative yield (i.e., it may lose money on an operating basis). To the extent that interest rates fall, certain underlying obligations may be paid off substantially faster than originally anticipated. If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by the Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities. High levels of inflation and/or a significantly changing interest rate environment can lead to heightened levels of volatility and reduced liquidity.
Financial Institutions Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Financial Institutions Risk: Changes in the creditworthiness of financial institutions (such as banks and broker-dealers) may adversely affect the values of instruments of issuers in financial industries. Adverse developments in banking and other financial industries may cause the Fund to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to financial institutions. Other adverse developments that affect financial institutions or the financial services industry generally, or concerns or rumors about any events of these kinds or other similar risks, may reduce liquidity in the market generally or have other adverse effects on the economy or the Fund. In addition, the Fund may not be able to identify all potential solvency or stress concerns with respect to a financial institution or to transfer assets from one bank or financial institution to another in a timely manner in the event such bank or financial institution comes under stress or fails. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition of a financial institution.
Fluctuation of Net Asset Value Share Premiums and Discounts Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Fluctuation of Net Asset Value, Share Premiums and Discounts Risk: As with all exchange-traded funds, Fund Shares may be bought and sold in the secondary market at market prices. Although shares are listed on an exchange, there can be no assurance that an active secondary trading market will develop or continue. In addition, trading of shares in the secondary market may become less liquid or may be halted, for example, due to activation of market-wide“circuit breakers.” If trading halts or an unanticipated early closing of the listing exchange occurs, a shareholder may be unable to purchase or sell shares of the fund. The trading prices of Fund Shares in the secondary market may differ from the Fund's daily NAV per share and there may be times when the market price of the shares is more than the NAV per share (premium) or less than the NAV per share (discount). There may also be times when there is a wide bid/ask spread. These risks are heightened in times of market volatility or periods of steep market declines.
Income Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Income Risk: The Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by the Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by the Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates.
Issuer Specific Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Issuer-Specific Risk: Issuer-specific events, including changes in the financial condition of an issuer, can have a negative impact on the value of the Fund.
Limited Track Record Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Limited Track Record Risk: The Fund has a limited track record and there is no assurance that the Fund will grow quickly. When the Fund's size is small, the Fund may experience low trading volume, which could lead to wider bid/ask spreads. In addition, the Fund may face the risk of being delisted if the Fund does not meet certain conditions of the listing exchange. Any resulting liquidation of the Fund could cause elevated transaction costs for the Fund and negative tax consequences for its shareholders.
Low Short Term Interest Rates Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Low Short-Term Interest Rates Risk: During market conditions in which short-term interest rates are at low levels, the Fund's yield can be very low, and the Fund may have a negative yield (i.e., it may lose money on an operating basis). During these conditions, it is possible that the Fund will generate an insufficient amount of income to pay its expenses, and will not be able to pay its scheduled dividend.
Management Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Management Risk: The Fund is actively managed. The Adviser's judgments about the attractiveness, relative value, or potential appreciation of a particular sector, security, commodity or investment strategy may prove to be incorrect, and may cause the Fund to incur losses. There can be no assurance that the Adviser's investment techniques and decisions will produce the desired results.
Market Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Market Risk: The Fund's investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile and prices of investments can change substantially due to various factors, including, but not limited to, economic growth or recession, changes in interest rates, inflation, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. Local, regional or global events such as war, military conflicts, acts of terrorism, trade policy changes or disputes, the threat or actual imposition of tariffs, natural disasters, the spread of infectious illness or other public health issues, or other events could have a significant impact on the Fund and its investments.
Mortgage Related and Other Asset Backed Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Mortgage-Related and Other Asset-Backed Securities Risk: Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed-income investments. The liquidity of mortgage-related and asset-backed securities may change over time. During periods of falling interest rates, mortgage- and asset-backed securities may be called or prepaid, which may result in the Fund having to reinvest proceeds in other investments at a lower interest rate. During periods of rising interest rates, the average life of mortgage- and asset-backed securities may extend, which may lock in a below-market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. Enforcing rights against the underlying assets or collateral may be difficult, and the underlying assets or collateral may be insufficient if the issuer defaults.
Non U S Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Non-U.S. Securities Risk: Non-U.S. securities (including depositary receipts) are subject to political, regulatory, and economic risks not present in domestic investments. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, legal and financial report standards comparable to those in the United States. Further, such entities and/or their securities may be subject to risks associated with currency controls; expropriation; changes in tax policy; greater market volatility; differing securities market structures; higher transaction costs; and various administrative difficulties, such as delays in clearing and settling portfolio transactions or in receiving payment of dividends. Securities traded on foreign markets may be less liquid (harder to sell) than securities traded domestically. Foreign governments may impose restrictions on the repatriation of capital to the U.S. In addition, to the extent investments are made in a limited number of countries, events in those countries will have a more significant impact on the Fund. Investments in depositary receipts may be less liquid and more volatile than the underlying shares in their primary trading market.
Rapid Changes in Interest Rates Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Rapid Changes in Interest Rates Risk: Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause the Fund to sell portfolio securities at a loss to satisfy those requests.
Repurchase Agreement Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Repurchase Agreement Risk: Repurchase agreements may be viewed as loans made by the Fund, which are collateralized by the securities subject to repurchase. If the Fund's counterparty should default on its obligations and the Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Fund may realize a loss.
Restricted Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Restricted Securities Risk: The Fund may hold securities that have not been registered for sale to the public under the U.S. federal securities laws. There can be no assurance that a trading market will exist at any time for any particular restricted security. Limitations on the resale of these securities may have an adverse effect on their marketability, and may prevent the Fund from disposing of them promptly at reasonable prices. The Fund may have to bear the expense of registering the securities for resale and the risk of substantial delays in effecting the registration. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.
Risks Related to ECDs ETDs and YCDs [Member]  
Prospectus [Line Items]  
Risk [Text Block] Risks Related to ECDs, ETDs and YCDs: Banks issuing ECDs, ETDs and YCDs are not necessarily subject to the same regulatory requirements that apply to domestic banks, such as loan limitations, examinations and reserve, accounting, auditing, recordkeeping and public reporting requirements. Obligations of foreign issuers also involve risks such as future unfavorable political and economic developments, withholding or other tax, seizures of foreign deposits, currency controls, interest limitations, and other governmental restrictions that might affect repayment of principal or payment of interest, or the ability to honor a credit commitment.
US Government Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] U.S. Government Securities Risk: Certain U.S. government securities are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congres sional appropriations, and their securities are not issued by the U.S. Treasury, are not supported by the full faith and credit of the U.S. government, and involve increased credit risks.
Variable and Floating Rate Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Variable and Floating Rate Securities Risk: During periods of increasing interest rates, changes in the coupon rates of variable or floating rate securities may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield.
Zero Coupon Bond Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block] Zero-Coupon Bond Risk: Zero-coupon bonds usually trade at a deep discount from their face or par values and are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities that make current distributions of interest.
Risk Lose Money [Member]  
Prospectus [Line Items]  
Risk [Text Block] As with all investments, there are certain risks of investing in the Fund. The Fund Shares will change in value, and you could lose money by investing in the Fund.
Risk Not Insured Depository Institution [Member]  
Prospectus [Line Items]  
Risk [Text Block] An investment in the Fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Risk Not Insured [Member]  
Prospectus [Line Items]  
Risk [Text Block] An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Risk Money Market Fund Price Fluctuates [Member]  
Prospectus [Line Items]  
Risk [Text Block] Because the share price of the Fund will fluctuate, when you sell your shares they may be worth more or less than what you originally paid for them.
Risk Money Market Fund May Impose Fees or Suspend Sales [Member]  
Prospectus [Line Items]  
Risk [Text Block] The Fund may impose a fee upon sale of your shares. The Fund may impose a fee upon the sale of shares by Authorized Participants. The Fund generally must impose a fee when net sales of Fund shares exceed certain levels.
Risk Money Market Fund Sponsor May Not Provide Support [Member]  
Prospectus [Line Items]  
Risk [Text Block] The Fund's sponsor is not required to reimburse the Fund for losses, and you should not expect that the sponsor will provide financial support to the Fund at any time, including during periods of market stress.