Core terms
Short Sale Restriction (SSR)
SSR usually means the Rule 201 short-sale price restriction after an NMS stock falls at least 10% from its prior regular-session close. It lasts for the rest of that day and the next trading day.
What traders should verify
Confirm the listing-market or broker status and its dates. The basic test addresses non-exempt short orders displayed or executed at or below the current national best bid. Specific displayed-order and short-exempt provisions apply; see the full guide.
Do not conflate
SSR is not a blanket short-selling ban or a halt. A rebound does not cancel it early. It triggers only during regular hours, but an existing restriction can apply beyond them while a current NBB is disseminated.