I use covered calls and frequently have assignments on expiration day. I was wondering when the settlement would actually occur. If I know my stock is being called away on expiration day can I make purchases on that day without actually borrowing money(assuming I have no cash)?
From my assignment experience, the proceeds from the assignment will hit the account on Sunday afternoon. You are free to trade on the following Monday.
Technically a stock trade on expiration Friday settles before an assignment/exercise but most firms give leeway for offsetting trades on friday and Monday as far as settlement/restrictions go.
That's just when they booked the assignment into your acct. You'll also notice most broker book stock into your acct immediately when you exercise prior to expiration even though the exercise instructions aren't transmitted to the OCC until after market close. The exercise technically takes place over night.