A stock trading halt is a temporary suspension of trading of a security imposed by regulators or exchanges. A trading halt may occur for a number of reasons, such as extreme price volatility or when the market is awaiting a substantial news release.

Information about current and historical trading halts, including the reasons for the halts, can be found on the NYSE and Nasdaq websites.

You can still place trades during a halt but they will not be processed until the halt is removed. Market orders placed during a trade halt will be queued to execute when trading resumes.