Whether to lock or float a mortgage rate is a crucial question for borrowers. And one that's not easy to answer.

When you float a loan, you haven't yet secured a lender’s quoted interest rate. Floating means you're willing to take the risk that interest rates will either not go up or that they will fall before you close your loan.

A rate lock is an agreement from a mortgage lender to hold a specific mortgage interest rate for a specific time period, even if rates rise. There are typically four elements to a rate lock. They should be clearly shown on the confirmation you receive once you notify the lender that you want to lock in your rate.