When you're offered a "rate lock" from your lender, it means that you are guaranteed to keep a particular interest rate for a determined period for the application process. This ensures that your interest rate will not rise as you are going through the application process.
Rate lock periods can vary in length, between 15 to 60 days, with the longer spans generally costing more. A lending institution will agree to hold an interest rate and points for a longer period, such as sixty days, but in exchange, the rate (and sometimes points) will be higher than with a rate lock of a shorter period.
There are other ways to get a reduced rate, in addition to agreeing to a shorter rate lock period. The more the down payment, the smaller the interest rate will be, as you will have more equity from the start. You can pay points to bring down your rate for the life of the loan, meaning you pay more up front. To a lot of people, this is a good option..
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