There are two parts to cashing out: selling your securities and transferring funds into your bank.
You can sell your securities during regular market hours, which are Monday through Friday, from 9:30 am to 4:00 pm ET (with the exception of certain stock market holidays).
After selling your securities during trading hours, you can then initiate a transfer to your bank account of your available cash balance. A cash withdrawal can take up to 5 days to process.