An exchange pauses trading when it judges that price discovery cannot work properly — usually pending significant news, or after a move large enough to trigger a volatility circuit breaker. Trading resumes through an auction that gathers orders before setting a new price.
When a company is about to release material information, an exchange can pause trading so everyone receives it at the same time. Without a pause, those who read fastest would trade against those still reading.
These halts are usually short and are followed by a re-opening auction, which is why a stock can resume at a very different price from where it stopped.
Exchanges also pause a stock automatically when it moves beyond a set band within a short window. The purpose is to interrupt a cascade — an order sequence feeding on itself faster than participants can react.
These are brief, often five minutes, and can repeat if the move continues after trading restarts.
A regulator can suspend trading over concerns about the accuracy of public information about a company. These last far longer and are a serious signal.
The distinction matters: a volatility halt says the price moved quickly, while a regulatory halt says something about the company's disclosures is in question.
Trading does not simply switch back on. Orders are collected and a single opening price is set where the most volume can trade, which is why the first print after a halt can be far from the last price before it.
A quote seen during a halt is an indication of where that auction might clear, not a price anything traded at.
One question, no account: what did you come here for, and did you find it? A person reads these, and they shape what gets written next.
From StockMotive — the honest why behind every market move. Educational information only, not investment advice.