Educational only, not financial advice. Market rules and thresholds can change — verify current specifics with the exchanges or your broker.

The three market-wide circuit breaker levels — 7%, 13%, and 20% single-day S&P 500 declines — trigger progressively longer halts. Here’s exactly what each does.

The three levels

Level 1 (−7%): if hit before 3:25pm ET, a 15-minute market-wide halt; at/after 3:25pm, no halt. Level 2 (−13%): same rule — 15-minute halt before 3:25pm, none after. Level 3 (−20%): at any time, trading halts for the rest of the day. Each level is measured from the prior day’s S&P close.

The logic of the timing rule

Levels 1 and 2 don’t halt after 3:25pm because there’s little session left — a pause would just delay the inevitable close. Level 3 halts anytime because a 20% single-day crash is catastrophic enough to stop trading entirely and reset overnight. The escalating severity matches the escalating decline.

7% and 13% buy a 15-minute timeout (before 3:25pm); 20% ends the day. Progressive brakes for a progressively worse crash.

What it means for a scalper

If a halt hits while you’re in a 0DTE position, you’re frozen — you can’t exit until trading resumes, and it may reopen at a very different price. That’s a real tail risk on a crash day, and a reason risk controls and defined-risk long options (max loss = premium) matter. These events are rare, but knowing the mechanics keeps you calm if one occurs.