what is a trading halt 
a trading halt is a temporary suspension of trading for a particular security or securities at one exchange or across numerous exchanges trading can be halted in anticipation of a news announcement to correct an order imbalance as a result of a technical glitch due to regulatory concerns or because the price of the security or an index has moved rapidly enough to trigger a halt based on exchange rules when a trading halt is in effect open orders may be canceled and options still may be exercised trading halts are different from a trading suspension ordered by the securities and exchange commission sec under u s securities law the sec may suspend public trading in any stock for up to 10 days to protect investors and the public interest 1