Market Structure/Trading mechanics
Why Stocks Get Halted and How to Find Today's Halts
Why exchanges halt a stock, what each halt code means, how a halt ends, what happens to open orders, and where to find the stocks halted today.
Where to find today's halts
This guide explains why stocks get halted and how to read a halt. The list of stocks halted right now, newest halt first and updated live, is the trading halt scanner. Keep it open beside this page.
The sample below is live too. It lists every security that is still halted in the current exchange halt snapshot, newest first, as of the time shown. Most halts last minutes, but a T12 can stay in force for months while the exchange waits for information, so older dates in the list are halts that have not lifted. A halt that lifted a minute ago may still be listed until the next refresh, and a halt called a minute ago may not be in it yet.
Live screen
Active trading halts
Each row carries a halt code. The rest of this page is a reading guide for that code: what family of halt it is, what has to happen for trading to resume, and what the stop means for orders you already have in. The full code table and the Limit Up-Limit Down arithmetic are in trading halts explained.
Two kinds of halt
A trading halt stops trading in one security on every US venue. The code tells you which of two families it belongs to:
| Family | Codes | Who calls it | How long |
|---|---|---|---|
| Regulatory | T1, T2, T12, H4, H9, H10 | The listing exchange, or the SEC for H10 | Until a condition is met; no fixed clock except H10 |
| Volatility | LUDP, LUDS, M | The listing exchange, automatically | Five minutes, extendable in five-minute steps |
Regulatory halts pause trading around information. T1 means material news is pending, T2 means it is being released, T12 means the exchange has asked the company for more information. H10 is an SEC trading suspension under Section 12(k) of the Exchange Act, which can run for up to ten business days. H4 and H9 relate to listing compliance and late filings.
Volatility pauses are mechanical. Under the Limit Up-Limit Down plan, each listed stock trades inside bands set at a percentage above and below the average price of the previous five minutes. For a Tier 2 stock (one outside the S&P 500, the Russell 1000 and certain exchange-traded products) that band is 10% when the prior close is above $3.00, 20% from $0.75 to $3.00, and the lesser of $0.15 or 75% below $0.75. If the best bid holds at the upper band, or the best offer at the lower band, for 15 seconds, the listing exchange pauses trading for five minutes. The bands double between 3:35 p.m. and 4:00 p.m. ET for Tier 2 stocks at or under $3.00. LULD does not apply to OTC stocks.
How a halt ends
The resumption is the part that matters for anyone holding or watching the stock, because it rarely happens at the last traded price.
- After a volatility pause, the listing exchange runs a reopening auction at the end of the five minutes. If the auction cannot find a price inside a widened range, the pause is extended, five minutes at a time. The first print after the pause is the auction price.
- After a news halt (T1, then usually T2), the exchange announces a resumption time, often with a quotation-only period before it so that orders can be entered and the book can form, then reopens with an auction.
- After a T12, there is no clock. Trading resumes when the exchange is satisfied with the company's response, which can take days or longer.
- After an H10 SEC suspension, the ten business days end, but trading does not automatically resume. An exchange-listed stock is often delisted around a suspension, and an OTC stock cannot be quoted again until a broker-dealer files the information Exchange Act Rule 15c2-11 requires.
A worked example of what the auction can do. Hypothetical Company X is halted at $4.00 under T1 at 10:15 a.m. At 10:45 a.m. the company announces an offering of 5,000,000 shares at $3.00, and the stock reopens at 11:00 a.m. through an auction that prints at $3.10.
| Order placed before the halt | What happens at reopening |
|---|---|
| Stop order to sell at $3.80 | Triggers on the $3.10 print and becomes a market order; it fills near $3.10, not $3.80 |
| Limit order to sell at $4.20 | Rests; it does not fill unless the stock trades back to $4.20 |
| Market order to buy, entered during the halt | Participates in the auction and fills at $3.10 |
Hypothetical figures.
The stop did exactly what a stop does; it just could not do it at $3.80, because no trade existed between $4.00 and $3.10. Some brokers cancel all open orders when a stock is halted. The only way to know is to check the broker's policy before a halt, not during one.
Why halts cluster in small caps
Three features of small listed stocks make this list skew toward them:
- Volatility. Cheap stocks get wider LULD bands, not narrower ones (20% from $0.75 to $3.00, and up to $0.15 or 75% below $0.75, against 10% above $3.00), but small caps routinely move by more than the extra width, so they reach a band far more often.
- News flow. Offerings, reverse splits, deficiency notices and financing agreements are the daily business of small issuers, and many of them are announced under a T1 halt at the company's request. The 8-K item codes guide maps the common announcements to the item they are filed under.
- Listing status. H4 and H9 halts, and the T12 requests that often precede a listing decision, are by definition about companies near the edge of their exchange's requirements.
None of this makes a halt good or bad for a position. It makes a halt a moment when the information set is about to change and the order book is about to be rebuilt from scratch.
How to find and follow halts on Signal8
- The full halts board, including halts that have already resumed today and the resumption times, is the trading halt scanner.
- During regular hours, Halt Resumers lists stocks that resumed in the last 15 minutes, and LULD Runners lists stocks with two or more volatility pauses today that are still up on the day.
- The live SEC filings feed and the news feed are where the 8-K or press release behind a T1 or T12 usually surfaces.
- Open the company page from any row to read its recent filings, and its dilution tab if the news turns out to be an offering.
- For how halts fit into the wider mechanics of small-cap trading, see how to trade penny stocks.
FAQ
How long does a trading halt last?
It depends on the code. A Limit Up-Limit Down volatility pause lasts five minutes and can be extended in five-minute steps if the reopening auction cannot find a price. A news halt (T1 and T2) usually lasts from under an hour to a few hours, until the exchange sets a resumption time. A T12 has no fixed length. An SEC suspension (H10) runs up to ten business days, and resumption is not automatic when it ends.
Can I sell a stock while it is halted?
No trade can execute while a halt is in effect. You can usually enter, change or cancel orders during the halt, and those orders then participate in the reopening auction. A stop order is not a way out: it cannot trigger until trading resumes, and when it does it becomes a market order at whatever price the auction sets. Some brokers cancel open orders at a halt; check the policy for your account.
What does a T12 halt mean?
The exchange has requested additional information from the company and has halted trading until it receives it. The code does not say what was asked or why. T12 halts can follow unusual trading, a corporate announcement the exchange wants to understand, or a listing question, and they last until the exchange is satisfied, which can be days or longer.
Do OTC stocks get halted?
Not under the LULD plan, which applies only to exchange-listed stocks. OTC securities can still be halted by FINRA (for example around a corporate action or a regulatory concern) and suspended by the SEC under Section 12(k). After an SEC suspension, an OTC stock cannot be quoted again until a broker-dealer satisfies Exchange Act Rule 15c2-11.
A stock I am watching is not on the list. Is it halted or not?
The list is a snapshot refreshed on a schedule, so a halt called in the last few minutes may not appear yet and a halt that just lifted may still show. Check the halts screener for the latest state, and treat an absence as "not found in the snapshot" rather than as confirmation that the stock is trading.
Terms in this guide
- Trading halt
- A trading halt is a temporary stop in trading of a security ordered by its listing exchange or the SEC, for example pending material news, to request information, or after a volatility pause.
- Limit Up-Limit Down (LULD)
- Limit Up-Limit Down (LULD) is the US market-wide rule that keeps each stock trading within price bands around a recent average and pauses trading for five minutes if a band is not restored.
- Form 8-K
- A Form 8-K is the SEC current report a public company files, generally within four business days, to disclose material events such as agreements, offerings, executive changes and listing notices.
- Reverse stock split
- A reverse stock split is a corporate action combining existing shares into fewer shares, cutting the share count and raising the per-share price by the same ratio; ownership percentages stay the same.
Try it on Signal8
See this in live data with Trading halt scanner.
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Educational content only. Signal8 is not a broker-dealer or investment adviser, and nothing here is a recommendation to buy or sell any security.