US trading halt reason codes, explained
What each halt code on the NASDAQ / UTP feed actually means, how long it typically lasts, and what it implies for a position you are already holding.
Volatility pause
- LUDP — Volatility Trading Pause (Limit Up-Limit Down) 28 today
The stock traded outside its Limit Up-Limit Down price band for 15 straight seconds. - M — Volatility Trading Pause (non-NASDAQ listed) 8 today
The same Limit Up-Limit Down volatility pause, reported for a security listed away from NASDAQ. - T5 — Single Stock Trading Pause
A legacy single-stock pause triggered by an outsized short-interval price move.
News halt
- T1 — News Pending
The company has told the exchange material news is coming. Trading stops BEFORE it is released. - T2 — News Released
The news is out. The market is being given time to read it before quoting resumes.
Resumption
- T3 — News and Resumption Times 9 today
The exchange has published when quoting and trading will restart. - C11 — Trade Halt Concluded
A halt has ended and normal trading is restored.
Regulatory halt
- T6 — Extraordinary Market Activity
The exchange believes trading in the stock is being affected by a systems or dissemination problem. - T12 — Additional Information Requested 13 today
The exchange has asked the company a question and is holding the stock until it answers. - H4 — Halt Non-Compliance
The issuer is out of compliance with exchange listing rules. - H9 — Halt Filings Not Current
The company's SEC filings are delinquent. - H10 — SEC Trading Suspension
The SEC itself has suspended trading in the security. - H11 — Regulatory Concern 2 today
A regulatory halt for a matter outside the standard categories.
Derivative halt
- T8 — ETF Component Halt
An ETF or index product is halted because the instruments underneath it are halted.
Listing event
- D — Security Deletion
The security is being removed from the exchange. - C3 — Issuer Corporate Action
Trading is stopped for a corporate action on the security.
IPO
- IPO1 — IPO Issue Not Yet Trading
A newly listed security has not opened for trading yet. - IPOQ — IPO Released for Quotation
Quoting has been released ahead of the first trade.
Market-wide
- MWC1 — Market Wide Circuit Breaker — Level 1
The S&P 500 fell 7% from the prior close. All US equity trading stops. - MWC2 — Market Wide Circuit Breaker — Level 2
The S&P 500 fell 13% from the prior close. - MWC3 — Market Wide Circuit Breaker — Level 3
The S&P 500 fell 20% from the prior close.
The halt is the reaction. The news came first.
Codes tell you the category of event. They never tell you the content of it.
By the time a symbol appears on this page, the thing that moved it has already crossed a wire somewhere. If you want to be reading the release rather than the halt notice, you need a feed measured in seconds, not refresh cycles.
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