Individual Stock Trading Halts,
Fully Explained
Sometimes it's not the whole market — just the one stock you're watching that suddenly stops quoting. This is a different mechanism from a circuit breaker. We cover the types of halts and what to watch for when trading resumes.
What Is a Trading Halt?
A Trading Halt is when the exchange temporarily suspends trading in a specific stock. Unlike a circuit breaker, which stops the entire market when the index drops sharply, a trading halt applies only to that one stock. Every other stock keeps trading normally.
Main Types of Trading Halts
1. LULD Volatility Halt (Limit Up-Limit Down)
Triggered automatically when the price moves outside a reference band within a short window. It usually lasts around 5 minutes, after which the stock resumes trading within a new band. This type shows up relatively often on stocks that are surging.
2. News Pending Halt
Right before or after a company announces material news (an M&A deal, clinical trial results, an earnings revision, and so on), the exchange can voluntarily halt the stock to give the market time to fully digest the information. This can last far longer than an LULD halt — anywhere from a few hours to more than a day.
3. Regulatory or Investigation-Related Halt
The SEC (Securities and Exchange Commission) can also directly halt trading in a specific stock over concerns like the spread of false information or suspected market manipulation. In this case, the resumption time is uncertain and the halt can drag on without advance notice.
How the LULD Band Is Set
An LULD volatility halt sets an upper and lower band based on the average price over the preceding 5 minutes, and triggers when the price moves outside that band. The band's width varies depending on the stock's price level and the time of day (wider bands are allowed right after the open and right before the close). That means the same-sized price move triggers a halt more easily on a low-priced stock and less easily on a high-priced one. This is also why LULD halts are observed more often on low-liquidity small caps.
What to Watch For When Trading Resumes
Once a halt lifts, the buy and sell orders that piled up during the halt all get reflected at once, so the price often jumps sharply right after resumption. If it was a news-pending halt in particular, the content of that news can produce a gap up or gap down immediately upon resumption. The first few minutes after resumption tend to have wide spreads and high volatility, so a cautious approach is warranted.
How to Read the Halt Codes You See on Screen
Trading-halt reasons are often shown as a letter-plus-number code. Common ones include T1 (news pending), T2 (resumption pending after a news release), T6 (single self-regulatory-organization action), and T12 (additional information requested). The code itself doesn't indicate a level of risk — what the underlying news or reason actually is is the information that actually matters. Rather than jumping to a conclusion from the code alone, it's worth building the habit of checking the reason description in the exchange's notice as well.
Comparison With a Circuit Breaker
| Circuit Breaker | Trading Halt | |
|---|---|---|
| Scope | The entire market (every stock) | 1 individual stock |
| Trigger | S&P 500 index decline percentage | Individual stock's price move, news, or regulation |
| Duration | 15 minutes, or until market close | Minutes to days (varies by reason) |
The trigger criteria and timing structure for both mechanisms are covered in detail in the complete guide to circuit breakers and side cars.