Finally, with a float-down, you can only reset your rate once, after which it has switched to a simple lock. So, if you get a 60-day free float for an interest rate of 4.5 percent, then the interest goes down and you use the float two weeks later to bring your rate down to 4.375 percent, you can`t cut it further if interest rates continue to fall to 4.25 percent in the coming weeks. . . .