0000356173 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class4ComboPROMember fmr:S000004818Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class4ComboPROMember fmr:S000004819Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class3ComboPROMember fmr:S000004820Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class3ComboPROMember fmr:S000004822Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class3ComboPROMember fmr:S000004823Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class3ComboPROMember fmr:S000004818Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class3ComboPROMember fmr:S000004819Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-SelectComboPROMember fmr:S000004820Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-SelectComboPROMember fmr:S000004822Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-SelectComboPROMember fmr:S000004823Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-SelectComboPROMember fmr:S000004818Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-SelectComboPROMember fmr:S000004819Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class1ComboPROMember fmr:S000004820Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class1ComboPROMember fmr:S000004822Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class1ComboPROMember fmr:S000004823Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class1ComboPROMember fmr:S000004818Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class1ComboPROMember fmr:S000004819Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class2ComboPROMember fmr:S000004820Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class2ComboPROMember fmr:S000004822Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class2ComboPROMember fmr:S000004823Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class2ComboPROMember fmr:S000004818Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-Class2ComboPROMember fmr:S000004819Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-InstitutionalComboPROMember fmr:S000004820Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-InstitutionalComboPROMember fmr:S000004822Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-InstitutionalComboPROMember fmr:S000004818Member 2024-04-02 2024-04-02 0000356173 fmr:FIMMFunds-InstitutionalComboPROMember fmr:S000004819Member 2024-04-02 2024-04-02 iso4217:USD pure 497 2023-03-31 false 0000356173 N-1A Fidelity Colchester Street Trust Supplement to the Fidelity® Investments Money Market Funds Class I May 30, 2023 Prospectus You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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.  You could lose money by investing in the fund.  Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.  The fund may impose a fee upon the sale of your shares. 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. Fidelity Investments and its affiliates, 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.  You could lose money by investing in the fund.  Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.  The fund may impose a fee upon the sale of your shares. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. Supplement to the Fidelity® Investments Money Market Funds Class II May 30, 2023 Prospectus You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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.  You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The fund may impose a fee upon the sale of your shares. 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. Fidelity Investments and its affiliates, 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.  You could lose money by investing in the fund.  Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.  The fund may impose a fee upon the sale of your shares. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. Supplement to the Fidelity® Investments Money Market Funds Class III May 30, 2023 Prospectus You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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.  You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The fund may impose a fee upon the sale of your shares. 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. Fidelity Investments and its affiliates, 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.  You could lose money by investing in the fund.  Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.  The fund may impose a fee upon the sale of your shares. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. Supplement to the Fidelity® Investments Money Market Funds Class IV May 30, 2023 Prospectus You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. Supplement to the Fidelity® Investments Money Market Funds Institutional Class May 30, 2023 Prospectus You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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.  You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The fund may impose a fee upon the sale of your shares. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. Supplement to the Fidelity® Investments Money Market Funds Select Class May 30, 2023 Prospectus You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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.  You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The fund may impose a fee upon the sale of your shares. 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. Fidelity Investments and its affiliates, 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.  You could lose money by investing in the fund.  Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.  The fund may impose a fee upon the sale of your shares. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. 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. Fidelity Investments and its affiliates, 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.