Quick answer

The SSR stock rule (short sale restriction, SEC Rule 201) kicks in when a stock falls 10% or more from the prior day’s close. For the rest of that day and the whole next trading day, short sales can only happen above the current national best bid, not at or below it.

Key takeaways
  • SSR is a stock market rule from the SEC, Rule 201 of Regulation SHO. It is not related to SSRI medicines.
  • Trigger: a 10% or larger drop from the prior day’s regular-hours close.
  • Duration: the rest of the trigger day plus the next trading day.
  • Short sellers can still short, but only above the national best bid.
  • Nasdaq publishes a daily list of stocks under the SSR stock rule.

You may see “SSR” next to a ticker in your trading app. It is a signal that the stock dropped hard and short selling is limited for now. Here is what it means for you.

What does SSR mean in stocks?

SSR stands for short sale restriction. It is the nickname for the “circuit breaker” in SEC Rule 201 of Regulation SHO. The SEC adopted it in 2010.

Its goal is simple. When a stock is already falling fast, the rule stops short selling from pushing the price down even further. It also lets people who own the stock sell first.

When does a stock go on SSR?

A stock goes on SSR when its price falls 10% or more below the prior day’s closing price. The SEC says the drop is measured with trades during regular trading hours, 9:30 a.m. to 4:00 p.m. Eastern.

The stock’s listing exchange makes the call and sends it out to the market. The rule covers exchange-listed stocks, known as NMS stocks.

How long does SSR last?

SSR lasts for the rest of the day it is triggered and the whole next trading day. If it starts on a Friday, it stays on through Monday.

The SEC says the restriction applies whenever quotes are being published, which can include extended hours. If the stock falls 10% again on the second day, SSR can be triggered again and extend one more day.

What changes when a stock is on SSR?

While SSR is on, a short sale cannot be executed or shown at or below the current national best bid. That is the highest price buyers are offering right now. In practice, short sellers must sell on an uptick, at a price above the bid.

Here is what that means for different traders:

  • If you own the stock: you can sell normally. The rule only limits short sales.
  • If you short: you can still short, but only above the bid, so fills may be harder.
  • If you are watching: SSR can slow down selling pressure, but it does not stop a stock from falling.

How can I check if my stock is on SSR tomorrow?

Nasdaq Trader publishes a daily Rule 201 list of stocks with the short sale restriction in effect. Many trading platforms also show an SSR flag next to the ticker.

A simple rule of thumb: if a stock closed down 10% or more from the prior close today, it will usually still be on SSR tomorrow. Always confirm with the official list.

Why does the SSR stock rule matter for small caps?

Small caps often move 10% in a day, so SSR shows up often. Big drops often follow news like an offering or a reverse split. If trading gets wild, a stock may also be halted.

Frequently asked questions

What is the SSR stock rule?

The SSR stock rule is SEC Rule 201, the short sale restriction. When a stock drops 10% or more from the prior close, short sales can only happen above the national best bid for the rest of that day and the next trading day.

Does SSR mean the stock will go up?

No. SSR only limits how short sales are priced. It can ease selling pressure, but the stock can still keep falling if many owners are selling.

Can I sell my shares when a stock is on SSR?

Yes. If you own the shares, you can sell them as usual. The SSR stock rule only applies to short sales.

How long does SSR last?

It lasts for the rest of the day it is triggered and the full next trading day. It can be triggered again if the stock drops another 10% on that next day.

Where can I find the SSR list?

Nasdaq Trader publishes a daily list of stocks under the Rule 201 short sale restriction. Many brokers also show an SSR flag on the ticker.

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Sources

Not financial advice. This article is for educational purposes only and is not financial, investment, legal or tax advice. It is published by Trade Conquest, owned and operated by Nite Cat, LLC. Rules change; check the cited official sources for the latest version. Trading carries a risk of loss. Trade Conquest does not recommend buying or selling any security.