Cboe BZX Files New Regular 'til Post Market Order Instruction

Cboe BZX Exchange filed a rule change with the SEC to add a new time-in-force instruction called Regular ‘til Post Market (RTP). The filing, published September 10, would let a qualifying limit order trade during regular U.S. equity-market hours and remain eligible during BZX’s after-hours session if it is not fully executed. Any remainder would expire at the end of that after-hours session, which runs to 8 p.m. Eastern Time.

The proposal is a venue-level change, not a universal instruction that every retail trading app will immediately expose. BZX says RTP would be available as an optional time-in-force designation and would be incorporated into its order-handling, opening-process and auction rules. RTP orders submitted ahead of the opening could participate in the opening auction under the proposed treatment; the filing also describes corresponding rules for priority and handling after the auction.

The SEC notice says BZX filed the change as non-controversial. The exchange identified an early-fourth-quarter 2026 implementation target and said it would announce the effective implementation date in a Trade Desk Notice.

Why it matters

For traders and brokers routing to BZX, the proposal could reduce the need to enter separate regular-session and after-hours limit orders. It does not turn a limit order into a guaranteed fill: after-hours liquidity, spreads and price volatility can differ materially from the regular session. Traders should confirm whether their broker supports the instruction, where an order is routed, and the session in which it remains active.

What to watch next

Watch for BZX’s implementation notice and broker-platform release notes. The SEC filing provides for public comments, and the exchange can still specify the operational rollout details.