Our default leans toward locking. Most people would rather lock and be a little wrong than float and be a lot wrong, and for a decision this stressful that is usually the right instinct. A lock is one-way insurance. It protects you if rates rise, but you do not automatically get the improvement if rates fall, because the lender pays a real cost to hedge your rate in the market. Most lenders offer a float-down, though usually only to within about an eighth of the better rate. Start with whether a move against you would actually hurt: - If an eighth of a percent higher would push you past what you qualify for or comfortably afford, or you are already near your debt-to-income ceiling, lock and sleep well. - If a small move would not change your life, you have room to float. Rates tend to rise faster than they fall, though, so floating carries lopsided risk. - Time to closing matters. Inside 30 days, we lean lock. At 45-plus days there is more room to float while staying in close contact. Either way, set a personal stop-loss: decide the worst move you will tolerate and lock the instant it hits. Two practical notes. Your rate is only truly locked when your Loan Estimate says "locked" with an expiration date and terms, so never rely on a verbal promise. And on new construction, the builder's lender often offers extended locks (90 to 180 days), sometimes with a float-down, worth comparing against an outside lender. Floating is a bet, and the call stays yours to make with the trade-offs in view. Treat any rate prediction as a guess, because nobody can promise where rates go. If you want us to walk your specific numbers and lock strategy, that is what the free Roadmap conversation (about 20 minutes) is for.