Trading halts and halt codes explained
A halt stops trading in one stock, or in the whole market, for a stated reason. The code on the halt says which kind it is — and the kind decides how long it usually lasts and how the stock reopens.
Why stocks get halted
Exchanges halt trading for two broad reasons. Regulatory halts give the market time to absorb material news, or stop trading while there is a question about the company. Volatility pauses stop a stock that moves too far, too fast. Separately, the SEC itself can suspend trading in a stock.
Volatility pauses: limit up–limit down
Under the Limit Up–Limit Down plan, every listed stock trades inside a price band around a reference price — the average price of its trades over the preceding five minutes. When the best offer falls to the lower band, or the best bid rises to the upper band, the stock enters a limit state. If that does not clear within 15 seconds, the listing exchange declares a five-minute trading pause, shown as LUDP.
The band is 5% either side for Tier 1 stocks — those in the S&P 500 or the Russell 1000, and some exchange-traded products — priced above $3, and 10% for other stocks above $3. From $0.75 to $3 it is 20%, and below $0.75 the lesser of $0.15 or 75%. From 3:35 p.m. Eastern to the close, the bands double for Tier 1 stocks and for Tier 2 stocks at $3 or below.
After five minutes, the listing exchange reopens the stock through an auction, and the pause can be extended by another five minutes. A stock paused in the last ten minutes of the day is not reopened; the exchange runs its closing process instead.
News halts
A news halt stops trading while material news goes out — results, a merger, trial data, a financing — so that everyone has it before trading restarts. It shows as T1, news pending, and moves to T2, news released, once the news has begun to disseminate. T3 then posts two times: when quoting can begin, and, later, when trading resumes. The gap between them lets orders build up, so the stock can reopen at a price that reflects the news.
Market-wide circuit breakers
If the S&P 500 falls 7% (Level 1) or 13% (Level 2) from the previous close before 3:25 p.m. Eastern, trading halts in every US stock for 15 minutes. At or after 3:25 p.m., those two levels do not halt trading, and each can halt the market only once a day. A 20% fall (Level 3) halts trading for the rest of the day, at any time.
SEC trading suspensions
Halts come from the exchanges. The SEC can separately suspend trading in a stock for up to 10 trading days, shown as H10. An exchange-listed stock can trade again as soon as the suspension ends; an OTC stock cannot be quoted again until a broker meets Rule 15c2-11 and files a Form 211 with FINRA.
Halt codes
The codes as Nasdaq publishes them, for the halts you will see most.
- T1
- Halt — news pending.
- T2
- Halt — news released. The news has begun to disseminate; trading is still halted.
- T3
- News and resumption times: when quoting can begin, and when trading resumes.
- T6
- Halt — extraordinary market activity.
- T8
- Halt — exchange-traded fund (ETF).
- T12
- Halt — additional information requested by Nasdaq.
- H4
- Halt — non-compliance.
- H9
- Halt — not current.
- H10
- Halt — SEC trading suspension.
- H11
- Halt — regulatory concern.
- LUDP
- Volatility trading pause, under limit up–limit down.
- LUDS
- Volatility trading pause — straddle condition.
- MWC1–3
- Market-wide circuit breaker halt, Level 1, 2 or 3.
- MWC0
- Market-wide circuit breaker halt carried over from the previous day.
- M1
- Corporate action.
- M2
- Quotation not available.
- IPO1
- IPO issue not yet trading.
- O1
- Operations halt.
In TickerRoom
The Halts Scanner posts each halt the moment it prints, with the reason code attached where the exchange provides one, and a separate alert when the stock resumes.