A trading suspension is an order by a securities regulator or an exchange that stops all trading in a security for a period, usually because investors lack reliable information about the issuer. Typical grounds are a failure to publish accounts on time, doubts about the accuracy of public statements, suspected market manipulation, insolvency proceedings, or a pending transaction that changes the nature of the company.
A suspension differs from a trading halt mainly in length and seriousness: a halt lasts minutes or hours, while a suspension can run for days, months or longer. In the United States the Securities and Exchange Commission may suspend trading in a security for up to ten business days. In the European Union a suspension ordered by a national regulator generally applies on every venue trading the instrument. Holders cannot sell during the period, and a prolonged suspension often ends in the delisting process.