The Financial Conduct Authority has published final rules for the Private Intermittent Securities and Capital Exchange System (PISCES), a new type of private stock market designed to enable intermittent secondary trading in shares of private companies. The regime will be delivered through a sandbox, with trading expected to begin later in 2025. PISCES platforms will allow private companies to broaden access to investors and provide exit opportunities for existing shareholders, while retaining controls such as setting floor and ceiling prices and influencing who can buy their shares. Access will be limited to institutional investors, high-net-worth individuals, sophisticated investors and employees of participating companies, and investors will be provided with information on the risks involved. Trading systems could include periodic auctions and occasional, time-limited periods of continuous trading, using Financial Markets Infrastructure sandbox powers. The sandbox is open and firms wishing to run a PISCES platform must apply to the FCA, after which approved operators can run intermittent trading events. The FCA and government plan to use lessons from the sandbox to refine the framework ahead of a permanent regime expected in 2030.