melvin, don't know which service u use, i.e. Ameritrade, Scotrade etc. On Ameritrade, if you have owned a stock for at least 3 business days and sell it your money is immediately available for a new purchase. But, if it has not been three days you will have to wait for however much time remains until the three days are up before access to the cash. Cash will show in your account balance but when u try to make a purchase the transaction will be denied. So, example, because of Thanksgiving, if u bought Wed., and sold Fri,it may be next Wed. before you can use the cash counting Fri., Mon, and Tues. as the three business days. Possibility may be able to get at it Tue.
If you've held the stock for 3 days no problem.