When you are offered a "rate lock" from a lender, it means that you are guaranteed to get a specific interest rate over a certain number of days for your application process. This ensures that your interest rate can't rise while you are going through the application process.
Although there are various lengths of rate lock periods (from 15 to 60 days), the longer ones are usually more expensive. You can get a longer period for your lock, but in doing so, will most likely have a higher interest rate than you would with a shorter period
In addition to opting for the shorter lock period, there are several ways you may be able to attain the best rate. A larger down payment will get you a lower interest rate, because you will have a good deal of equity at the start. You can pay points to improve your interest rate over the loan term, meaning you pay more initially. For a lot of people, this makes financial sense..
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