A rate "lock" or "commitment" is a lender's promise to set a certain interest rate and a specific number of points for you for a specified period of time during your application process. This ensures that your interest rate won't grow during the application process.
Rate lock periods can vary in length, anywhere from 15 to 60 days, with the longer ones generally costing more. You can get a longer period for your lock, but in choosing this option, will most likely have a higher rate than you would have with a shorter rate lock span of time
There are more ways to get a reduced rate, besides going with a shorter rate lock period. The more the down payment, the better the rate will be, as you will have more equity from the start. You can pay points to improve your rate for the loan term, meaning you pay more up front. 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'll pay more up front, but you will come out ahead in the end.
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