When you're promised a "rate lock" from a lender, it means that you are guaranteed to keep a specific interest rate over a certain number of days for your application process. This means your interest rate can't rise during the application process.
Rate lock periods can be various lengths of time, anywhere from fifteen to sixty days, with the longer period usually costing more. A lending institution will agree to lock in an interest rate and points for a longer period, such as sixty days, but in exchange, the rate (and sometimes points) will be more than with a rate lock of a shorter period.
There are other ways to get a lower rate, besides going with a shorter rate lock period. The more the down payment, the lower your interest rate will be, since you will have more equity from the start. You could opt to pay points to reduce your interest rate for the loan term, meaning you pay more initially. To a lot of people, this makes sense and is a good deal..
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