What is a "rate lock period"?
Freezing the Rate
When you're offered a "rate lock" from your lender, it means that you are guaranteed to keep a particular interest rate for a certain number of days for your application process. This means your interest rate won't rise as you are going through the application process.
While there may be a choice of rate lock periods (from 15 to 60 days), the extended spans are typically more expensive. You can get a longer period for your lock, but in choosing this option, will probably have a higher interest rate than you would have with a shorter rate lock span of time
More Ways to Get a Great Interest Rate
There are more ways to get a low rate, besides agreeing to a shorter rate lock period. A bigger down payment will give you a reduced interest rate, since you will have a good deal of equity at the start. You can pay points to improve your rate over the loan term, meaning you pay more initially. One strategy that is a good option for many people is to pay points to reduce the rate over the life of the loan. You will pay more up front, but you'll come out ahead in the long run.