Equities trade in sessions. Nights, weekends and holidays close the underlying market while the on-chain token may still change hands around a thin book. A closed session is therefore not an oracle problem: a price can be perfectly fresh and still unexecutable.
The Risk Lab has a separate closed-session switch and a Weekend-gap preset. The scenario reports no executable route until the next session, and applying the gate sets the ledger to its closed mode, which blocks new exposure with a session-specific reason instead of an oracle message.
The design answer that avoids a forced sale into a closed market is the paired in-kind exit: both claim classes burn a common fraction and receive raw units plus cash. An issuer transfer freeze still blocks it, because a frozen token cannot move even when the session reopens.
Session states here are manual research controls, not a real market calendar. No live session, holiday schedule or issuer permission is configured.