Trading halts: see stock halts and resumptions as they happen
A trading halt scanner shows which stocks have been halted and when they resume trading, so you can follow stock halts as they happen. Bufflo’s Halt table streams each stock’s halted or resumed status with the time and exchange, can be narrowed with your own screener rules, and can play a sound or send a phone alert when a halted stock resumes.
A halt stops trading in a stock, often at the most interesting moment: in the middle of a fast move or just before material news. When trading resumes, price can open well away from where it stopped. If you trade fast-moving small caps, knowing what is halted, and when it comes back, is part of the job.
Try it: ask Bufflo AI
- Ask Bufflo AI“Alert me when any US stock resumes trading after a halt”
- Ask Bufflo AI“Show halts only for stocks under $20 with float below 20 million”
- Ask Bufflo AI“Alert me when AMD resumes trading after a halt”
Why do stocks get halted?
Exchanges and regulators halt trading for a few broad reasons, and each has its own code. These are the ones active traders see most on Nasdaq:
| Code | Meaning |
|---|---|
| T1 | Halted pending material news |
| T2 | News has started being disseminated |
| T12 | Halted pending additional information requested by Nasdaq |
| LUDP | Volatility trading pause under limit up-limit down |
| H10 | The SEC has suspended trading |
| MWC1 to MWC3 | Market-wide circuit breaker, levels 1 to 3 |
News halts usually last until the news is out and the exchange is satisfied the market has had time to absorb it. Volatility pauses are shorter and follow fixed rules.
How limit up-limit down pauses work
Limit up-limit down (LULD) is the mechanism behind most short volatility halts in US stocks. Each stock has a price band above and below its average price over the preceding five minutes. If the price moves to the band and does not come back inside it within 15 seconds, trading pauses for five minutes.
- Bands are 5%, 10%, 20%, or the lesser of $0.15 or 75%, depending on the stock’s price and tier.
- Tier 1 covers the S&P 500, the Russell 1000 and select exchange-traded products. Tier 2 covers other NMS stocks.
- LULD applies during regular trading hours, 9:30 a.m. to 4:00 p.m. ET.
- Bands double in the last 25 minutes of the session for Tier 1 stocks and for Tier 2 stocks at or below $3.00.
Because low-priced Tier 2 stocks have wider bands and move fast, the same small cap can pause several times in one session. Watching halts and resumptions in real time is how momentum traders keep up with that.
Market-wide circuit breakers
Separately from single-stock halts, the whole market can halt if the S&P 500 falls sharply in one day:
| Level | S&P 500 decline | What happens |
|---|---|---|
| Level 1 | 7% | Trading halts for 15 minutes, if triggered before 3:25 p.m. ET |
| Level 2 | 13% | Trading halts for 15 minutes, if triggered before 3:25 p.m. ET |
| Level 3 | 20% | Trading halts for the rest of the day |
Watching halts in Bufflo
- Halt table: a live list of halted and resumed stocks, with the time of the latest status change and the exchange.
- Your own filters: apply a saved screener to the Halt table, so you only see halts in stocks that match your price, float or volume rules.
- Sound alerts: hear when a new row appears instead of watching the table.
- Resumption alerts: create an alert that fires when a halted stock resumes, delivered in the web app and as a phone notification.
- Linked chart and news: click a halted stock to load its chart, with a News table beside it to find the reason.
Pair the Halt table with a momentum scanner to see what was moving before the pause, and with custom alerts to be told when it trades again.
Why resumptions matter
When a halted stock reopens, the first trades can print far from the last price before the halt, in either direction. Orders queued during a halt can execute at prices you did not expect. Many traders watch the reopening rather than trade into it, and every trader should know how their broker handles orders during a halt.
Frequently asked questions
Why do stocks get halted?
Most often for pending news (Nasdaq code T1) or a limit up-limit down volatility pause (LUDP). Exchanges also halt stocks to request more information, and the SEC can suspend trading.
What is a T1 halt?
T1 is the Nasdaq code for a stock halted pending material news. The halt usually lasts until the news is out and the exchange decides the market has had time to absorb it.
How long does a trading halt last?
A limit up-limit down pause lasts five minutes. A news halt lasts until the news has been released and the exchange reopens trading, which can take minutes or longer. A Level 1 or Level 2 market-wide circuit breaker halts trading for 15 minutes; Level 3 halts it for the rest of the day.
Can I get alerted when a stock resumes trading?
Yes. Create an alert that fires when a halted stock resumes, for all US stocks or only the ones you choose. Alerts can appear in the web app and as phone notifications.
Does the Halt table show every halted stock?
The Halt table streams halt and resumption events as Bufflo receives them. You can show all of them or apply a screener to keep only the stocks you care about. Data timing depends on exchanges and data providers, so confirm critical information with your broker.
Can I trade a stock while it is halted?
No. Trading on the listing exchange and other venues stops during a halt. Orders may be accepted by your broker and queued, then execute when trading resumes, sometimes at very different prices.
Try it on a live workspace.
Open Bufflo in your browser, describe what you want in plain English, and adjust everything yourself. No install, no code.
Sources
Market monitoring and analysis, not a brokerage. Not investment advice. Backtested results do not guarantee future performance. Data availability and refresh rates depend on your plan and market data providers.
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