If you’re not asking that question, you should be because rates aren’t set in stone unless you specifically ask them to be.

By that, I mean locking in the mortgage rate you negotiate or agree upon with the bank/lender so even if rates change from one day to the next, your rate won’t.

Otherwise, you’re merely floating your mortgage rate, and thereby taking your chances. Without a rate lock, it’s really just a quote.

Think of a quoted mortgage rate like a stock price – until you actually buy/sell it, the price is subject to change. So until you lock, rates may worsen or improve.

Rates can generally be locked in for anywhere from 15 to 90 days or longer, with shorter lock periods cheaper than longer ones.

Nowadays, many lenders offer so-called “lock and shop” options that allow you to lock in an interest rate before you find a home.

There are pros and cons to those programs. The advantage being a guaranteed rate, the disadvantage being a potentially higher rate for the convenience.