SSR: the short-sale price test

Read the full guide

This lesson is a short recap. The full FennEdge guide, SSR explained: the 10% trigger, duration, and short-sale price test, owns this topic, with worked quotes, exceptions and sources. For order rejections and how to troubleshoot them, continue with SSR order rules.

Learning objectives

After this lesson you can:

• Compute the price at which a stock meets the SSR trigger, and name the reference price it uses.
• State how long the restriction lasts, including across a weekend.
• Explain what the price test restricts, what it leaves alone, and how it differs from a halt, a locate and the threshold list.

Recap: SSR in five points

1. What it is. SSR is the common name for the short-sale circuit breaker in SEC Regulation SHO, Rule 201. It is a price test on short sales, not a ban on shorting and not a trading halt.

2. The trigger. The restriction is triggered when a stock's price falls 10% or more from its prior-day closing price, as determined by the listing market at the end of regular trading hours. The reference is that close: not today's open, not the intraday high, not your entry. The listing market makes the determination and disseminates it. SEC staff guidance says the trigger can only occur during regular trading hours (09:30–16:00 ET). An app's own "−10%" figure is not the official status.

An Illustrative example: Ferncastle Devices (fictional) closed yesterday at $8.00. The trigger level is $8.00 × 0.90 = $7.20. A regular-session trade at $7.20 or below meets the threshold; a fall from a $9.50 intraday high to $8.40 does not, because $8.40 is still above yesterday's close.

3. How long it lasts. Once triggered, the restriction applies for the rest of that day and the following trading day. A Friday trigger carries into Monday. A rebound above the trigger level does not end it early. A new 10% decline on the following day, measured from that day's prior close, triggers it again and extends it by another day. Once triggered, the test also applies outside regular hours whenever a national best bid is being disseminated under a national market system plan.

4. The price test. Trading centers must have policies to prevent a short sale from executing or being displayed at or below the current national best bid (NBB). The reference is the best bid across markets, not the last trade. In practice, a non-exempt short cannot hit the bid; it can rest at a price above the NBB and wait to be bought. A displayed short order priced above the NBB when first displayed can still execute if the bid later rises to it. Orders properly marked "short exempt" fall under specific exceptions; a locate does not make an order short exempt.

5. What it does not restrict. Selling shares you own and buying to cover a short are not short sales, so the test does not apply to them. SSR says nothing about borrow availability (HTB vs. ETB) or about delivery failures (Reg SHO threshold list), and it sets no price floor.

SSR and the overnight session: status as of 2026-10-06

Nasdaq's overnight session (21:00–04:00 ET) is scheduled to start on 2026-12-06, subject to readiness. What the primary sources show as of 2026-10-06:

• Verified: an existing restriction carries into the overnight session. Rule 201(b)(1)(ii) applies the test while a national best bid is disseminated under a national market system plan. The Nasdaq UTP SIP is scheduled to run 23 hours a day from 2026-12-06, with each new trading day starting at 21:00 ET. Its Extended Trading Hours FAQ (version 1, June 2026) says SSR states advance at the start of day, about 20:55 ET: "Active" becomes "Continued", and "Continued" becomes "Deactivated". So a restriction triggered during Monday's regular session continues through the trading day that starts at 21:00 ET Monday.
• Verified: the trigger is a regular-hours event. SEC staff guidance (Rule 201 FAQ, questions 1.2 and 2.1; page last reviewed or updated 2026-06-26) says the circuit breaker can only be triggered during regular trading hours. Under that guidance, a 10% decline that happens only in the overnight session would not trigger SSR.
• Unresolved: the session has not launched; we found no SEC guidance written specifically for the overnight session; and we did not verify how the consolidated feed for NYSE-listed and other non-Nasdaq stocks handles SSR states. Ask your broker how it flags SSR overnight. Re-check after 2026-12-06.

Apply it in FennEdge

• The Reg SHO tool shows the dated threshold list. It is not an SSR list; confirm SSR status with your broker or the listing market.
• In the Trading Journal, which holds broker-synced real fills only, compare your short entries on SSR days with your broker's order reports to see which orders rested above the bid and which did not fill.

Exercises

Three exercises follow this recap: a concept check on which short order price the test allows, a calculation of the trigger level, and a scenario about the day after a Friday trigger. Exercises, answers and progress are available after signing in.

Primary sources

• SEC Regulation SHO. Rule 201, circuit breaker (eCFR, up to date as of 2026-10-01).
• SEC Division of Trading and Markets. Responses to frequently asked questions concerning Rule 201, questions 1.2 and 2.1 (page last reviewed or updated 2026-06-26). Staff guidance, not a rule.
• Nasdaq UTP Plan. SIP Extended Trading Hours FAQ, version 1 (June 2026), question 14; UTP Data Feed Services Specification, version 4.1 (September 2026).

Sources checked 2026-10-06. Ferncastle Devices and its prices are fictional and Illustrative. This lesson is education, not a recommendation to buy or sell any security. Past patterns do not indicate future results.