0000028540 2026-06-16 2026-06-16 0000028540 fmr:FidelitySeriesCommodityStrategyFund-PROMember fmr:S000042145Member 2026-06-16 2026-06-16 0000028540 fmr:FidelityCommodityStrategyFund-RetailPROMember fmr:S000055837Member 2026-06-16 2026-06-16 497 2026-06-16 false 0000028540 N-1A Fidelity Oxford Street Trust Supplement to theFidelity® Series Commodity Strategy FundSeptember 29, 2025Prospectus The Bloomberg Commodity 3 Month Forward Total Return Index is a version of the BCOM where the lead and future contracts look three months ahead of the BCOM index contract calendar. The Bloomberg Commodity 3 Month Forward Total Return Index reflects the returns on a fully collateralized investment in the Bloomberg Commodity 3 Month Forward Index. This combines the returns of the Bloomberg Commodity 3 Month Forward Index with the returns on cash collateral invested using the Secured Overnight Financing Rate (SOFR). The SOFR is a secured overnight interest rate calculated by the Federal Reserve Bank of New York, derived from repurchase agreement transactions collateralized by U.S. Treasury securities. Supplement to theFidelity® Commodity Strategy FundSeptember 29, 2025Prospectus The Bloomberg Commodity 3 Month Forward Total Return Index is a version of the BCOM where the lead and future contracts look three months ahead of the BCOM index contract calendar. The Bloomberg Commodity 3 Month Forward Total Return Index reflects the returns on a fully collateralized investment in the Bloomberg Commodity 3 Month Forward Index. This combines the returns of the Bloomberg Commodity 3 Month Forward Index with the returns on cash collateral invested using the Secured Overnight Financing Rate (SOFR). The SOFR is a secured overnight interest rate calculated by the Federal Reserve Bank of New York, derived from repurchase agreement transactions collateralized by U.S. Treasury securities.