Fund Description: Fidelity Limited Term Bond ETF is an actively managed exchange-traded fund or Actively Managed ETF which is a separate investment portfolio of the Fidelity Merrimack Street Trust, an open-end investment management company. INVESTMENT OBJECTIVE: The Fidelity Limited Term Bond ETF seeks to provide a high rate of income. The Fund is an actively managed ETF and thus, does not seek to replicate the performance of a specific index, but rather uses an active investment strategy to meet its investment objective, however, an actively managed ETF may have an index-based benchmark. Accordingly, the ETF’s investment advisor, Fidelity Investments Money Management, Inc. (FIMM), has discretion on a daily basis to actively manage the Fund’s portfolio in accordance with the Fund’s investment objective and investment policies. The Fund's Index benchmark is the Fidelity Limited Term Composite Index. FUND STRATEGY: The Adviser normally invests at least 80% of the Fund's assets in investment-grade debt securities (those of medium and high quality) of all types and repurchase agreements for those securities. The Adviser uses the benchmark, Fidelity Limited Term Composite Index, as a guide in structuring the Fund and selecting its investments. The Adviser manages the Fund to have similar overall interest rate risk to the Index. The Adviser considers other factors when selecting the Fund's investments, including the credit quality of the issuer, security-specific features, current valuation relative to alternatives in the market, short-term trading opportunities resulting from market inefficiencies, and potential future valuation. The Fund normally maintains a dollar-weighted average maturity between two and five years. The Adviser allocates the Fund's assets among different market sectors (for example, corporate, asset-backed, or government securities) and different maturities based on its view of the relative value of each sector or maturity. The Adviser may invest the Fund's assets in securities of foreign issuers in addition to securities of domestic issuers and may also invest the Fund's assets in lower-quality debt securities. The Adviser may engage in transactions that have a leveraging effect on the Fund, including investments in derivatives, regardless of whether the Fund may own the asset, instrument, or components of the Index underlying the derivative, and forward-settling securities. The Fund's derivative investments may include interest rate swaps, total return swaps, credit default swaps, options (including options on futures and swaps), and futures contracts (both long and short positions) on securities, other instruments, and indexes. To earn additional income for the Fund, the Adviser may use a trading strategy that involves selling (or buying) mortgage securities and simultaneously agreeing to purchase (or sell) mortgage securities on a later date at a set price. FUND MANAGEMENT: Fidelity Investments Money Management, Inc. (FIMM) serves as the Adviser to the Fund.