Using API v2, you can submit and fill orders during pre-market and after-hours. Extended hours trading has specific risks due to the less liquidity. Please read through our disclosure for more details.

Currently, we support the following extended hours:

Pre-market: 9:00 - 9:30am

After-hours: 4:00 - 6:00pm

For more information please read the Alpaca Docs.

Understand Orders - Documentation | Alpaca
Alpaca API lets you build and trade with real-time market data for free.