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Short-Sale Restriction (SSR)

SEC Rule 201 price test that activates after a 10% intraday drop

The short-sale restriction (SSR) is an SEC Rule 201 price test that activates when a stock falls 10% or more from its previous close. While SSR is active, a short sale can only execute at a price above the current national best bid, so shorts cannot hit the bid and drive the price down.

In short
  • Trigger: a 10% or greater decline from the prior day's close. Once active, SSR stays on for the rest of the session and until the close of the next one.
  • The price test compares against the national best bid (NBB), not the last trade. A short must print strictly above the bid.
  • SSR slows a decline; it does not stop one. Long sellers are unrestricted, so a stock can keep falling under SSR.
How its calculated

How is Short-Sale Restriction (SSR) calculated?

Activation (SEC Rule 201):
  trigger: last sale price drops >= 10% below the prior day's closing price
  duration: the remainder of that session plus the next session's close

Price test while active (regular hours):
  short sale is permitted only at a price strictly above the NBB
  (national best bid); shorting at or below the bid is not permitted
  SSR does not apply to extended-hours trading

Rule 201 (the alternative uptick rule, adopted 2010) is a speed bump on shorting into a falling stock, a modernized version of the original uptick rule. The comparison price is the quoted bid, which is what made the 2010 version testable by modern order systems. Tapeboard's paper-trading simulator implements exactly this test: while SSR is flagged active on a symbol, a short order is repriced to the lowest permitted price above the NBB rather than rejected.

What traders use it for

What do traders use Short-Sale Restriction (SSR) for?

  • Explaining the tape after a big morning drop. Once SSR is on, the relentless bid-hitting stops and shorts must work above the bid, which often slows the slide and tightens the spread behavior.
  • Avoiding rejections in live or simulated trading. A short ticket under SSR must be priced above the bid or it will not execute; traders who do not know the rule read the rejection as a broker problem.
  • Gauging squeeze setups. SSR being active is evidence the name already fell hard today; combined with high short interest it marks names where the short side is operating under friction.
Worked example

Worked example

Worked example: $RIOT
SSR activates on a 10% morning drop

Suppose a $12 name closes Tuesday at $12.40 and Wednesday prints a low of $11.10, a drop of 10.5%. SSR activates and stays active through Wednesday's close and all of Thursday. A trader who wants to short at 13:00 ET Wednesday must price the order above the current NBB of $11.18; an order at $11.18 or lower does not execute (as of 2026-05-02, illustrative). In Tapeboard's simulator the same order is repriced to the lowest permitted price instead of filling through the bid.

Live data: /stock/RIOT.

Common pitfalls

What are common pitfalls of Short-Sale Restriction (SSR)?

  • SSR is not a short ban. Shorts can and do keep selling; they simply must price above the bid, which adds cost and delay, not prohibition.
  • Long sells are exempt. Panicked longs hitting the bid can push the stock down just as fast with SSR fully active.
  • Extended hours are exempt. After-hours shorting has no Rule 201 price test, so the after-hours tape can behave differently from the regular session.
  • The 10% trigger references the prior close, not the intraday high. A stock can be down 30% from its morning high without SSR if it never dropped 10% below the previous close.
Where it appears on Tapeboard

Where this metric appears on Tapeboard

Tapeboard's paper-trading simulator enforces the Rule 201 price test in its order engine: while SSR is flagged active on a symbol, short orders are repriced to the lowest permitted price above the national best bid (src/lib/shortSaleLogic.ts), matching the live-market rule.

Related TERMS

Related terms

  • Trading Halt: Halts are called by the exchange, not by the company or by brokers. News pending and volatility are the two most common triggers.
  • Short Interest: FINRA short-interest reports settle bi-monthly with a publication lag of about 10 business days from the report date.
  • Failures-To-Deliver (FTD): Bi-monthly SEC dataset, lag of about two weeks. Counts unsettled share volume per ticker per day.
Primary sources

Primary sources cited

See it live

See it live

The rule is real in the Tapeboard simulator: short a symbol while SSR is active and the order engine reprices your fill to the Rule 201 permitted price instead of executing through the bid.

Page review

Methodology last reviewed 2026-10-24 by Marcus Reilly, Editor at Tapeboard. Every claim on this page has a row in the citation registry. Glossary terms reverify on the Jan 15 / Apr 15 / Jul 15 / Oct 15 cron and any time the underlying primary-source publishes a methodology change. See methodology for the full fact-check process and corrections for the public correction log.

Disclaimer. This page is for educational and informational purposes only. Nothing on Tapeboard is investment advice. See the full risk disclaimer.