You lose, however, if the rates rise during the time period. The period of time during which you can lock with a floater is so many days before closing or some other time period. It's not a free for all. It's pretty well layed out. Setting the locks Whatever lock you choose, get the lock guarantee in writing.
Oral agreements are difficult to prove.
Unless your contract says otherwise, a rate lock could also prevent you from taking advantage of lower rates, should rates decrease. Lock in as many of the costs you can, the rate as well as points. That could be weeks away and rates could change unfavorably just as they have in recent days. Shop around for both the terms of the lock contract and its cost. Some lenders may charge you an upfront, nonrefundable fee should you withdraw your application, if your credit is denied, or if for some other reason you don't close the loan.