Quick definition A trading halt is a temporary suspension of trading in a security. Exchanges halt trading when a company is about to announce news, when there is potential market manipulation, or when there is confusion about the stock. What it is Trading halts typically last 15 minutes to an hour. When a trading halt is in effect, no trades can occur. The company must file a disclosure document explaining the reason for the halt. When trading resumes, all market participants have access to the same information. Halts are initiated by the exchange (NYSE, NASDAQ) or by the company itself when material news is pending. The SEC can also request a halt if there is concern about fraud or market disruption. Why it matters Trading halts protect investors by ensuring that news is disclosed fairly. Without halts, insiders could trade on non-public information before news is released, giving them an unfair advantage. Halts also give the market time to process information. When major news is announced, prices can swing wildly as traders process the implications. A halt prevents chaotic trading during this transition. Halt types A news halt is called when a company is about to announce earnings or other material news. A regulatory halt is called when there are concerns about fraud or market manipulation. A volatility halt is called when prices move extremely rapidly, giving traders time to assess what is happening. Practical example A pharmaceutical company is waiting for FDA approval of a drug. The stock is trading normally. When the FDA decision is coming, the exchange proactively halts trading to prevent insiders from trading ahead of the announcement. The halt gives the company time to prepare a disclosure. Insiders cannot buy or sell during the halt. When trading resumes, all investors see the news at the same time. The stock then finds a new equilibrium price. Market reaction to halts Markets often interpret a halt as a sign of pending news. Long halts can trigger speculation and fear. Short halts are routine and attract little attention. See also - Circuit Breaker - Insider Trading - Market Surveillance - Disclosure
