After Hours Market Law and Legal Definition

After hours market is the practice of trading a security after an exchange has closed. Securities, such as stocks and bonds, may change hands on organized markets and exchanges after regular business hours. After-hours trading occurs over the counter. Both listed and unlisted securities may be traded in after hours market. After-hours trading is often less liquid than regular trading since participation by market makers is voluntary, whereas market makers are required to serve as a counterparty for a security during trading hours.