There are two types of trading halts and delays -- regulatory and non-regulatory. The most common regulatory halt and delay happens when a company has pending news that may affect the security’s price (a "news pending" halt or delay). By halting or delaying trading, market participants can have time to assess the impact of the news. Another type of regulatory halt or delay happens when a market halts trading in a security when there is uncertainty over whether the security continues to meet the market’s listing standards. When a regulatory halt or delay is imposed by a security’s primary market, the other U.S. markets that also trade the security honor this halt. Securities exchanges, not the SEC, determine whether to impose a trading halt or delay in a stock. Securities exchanges are self-regulatory organizations (SROs), which means they have authority to develop and enforce their own rules and standards.