Should I lock my mortgage rate or let it float?

Lock when you're comfortable with the quoted rate and have a closing date in sight – a rate lock guarantees your rate for a set window (commonly 30–60 days) even if the market moves against you. Floating means betting rates will drop before you close, which can backfire if they rise instead. Most buyers lock once they're under contract, because the downside of a sudden rate jump usually outweighs the chance of a small dip. Ask about lock length and whether a float-down option lets you capture a lower rate if the market falls after you lock. If your closing might slip, confirm extension costs up front, since extending a lock often carries a fee.