Exchanges Propose Price-Band Protections for Overnight Stock Trading

National securities exchanges and FINRA proposed price-band protections to curb extraordinary volatility during overnight stock trading, limiting how far prices may move between 9:00 p.m. and 4:00 a.m. 

Under the proposal filed with the SEC, each primary listing exchange would calculate overnight price bands for its listed stocks and send them to the public data processors before 9:00 p.m. The bands would sit 20 percent above and below two reference prices - a stock's official closing price and its consolidated last sale as of 7:45 p.m. - with minimum bands of $1.00 for stocks closing under $1.00 and $3.00 for those at or above. Trading centers operating overnight would have to maintain policies reasonably designed to prevent trades outside the bands.

Unlike regular hours, the overnight session would have no automatic trading pauses. Instead, a primary listing exchange could declare a discretionary regulatory halt that would last the rest of the session, with no reopening auction, reflecting the thin overnight liquidity. The 20 percent parameter mirrors the static bands used by the alternative trading systems ("ATSs"), though the plan would use two reference prices rather than one.

The exchanges proposed a phased rollout. Phase 1 would set interim, static bands; Phase 2 - expected in 2027 - would add sliding bands and possibly recalibrated parameters. The exchanges said their analysis indicated minimal impact, with less than 0.1 percent of volume affected.

The proposal was published in the Federal Register and the comment deadline is set for June 25, 2026, ahead of the planned start of overnight exchange trading on December 6, 2026.