When to Lock Your Rate

A rate lock is one of the few genuinely free-feeling decisions in a mortgage that still deserves real thought. Here's the honest version — no urgency, no countdown clocks.

What a lock actually is

A rate lock is a commitment from the lender: this rate, at this pricing, held for you for a set window while your file moves to closing. Once locked, the daily churn of the bond market — everything described in what moves your rate — stops mattering to your loan. Rates can rise; yours doesn't. Rates can fall; yours doesn't, either. That's the trade.

An unlocked rate is called "floating." Floating means your final rate will be whatever the market offers on the day you do lock — better, worse, or the same.

Lock periods

Locks come in windows — commonly measured in days, sized to how long your loan will realistically take to close. Shorter locks carry the best pricing; longer locks cost a bit more, because the lender is absorbing more market risk on your behalf.

The practical rule: the lock should comfortably cover your closing date. A lock that expires two days before closing isn't a bargain — extensions exist, but they're an avoidable cost. When we lock a file, we match the window to the actual timeline in front of us: the appraisal, underwriting, and in South Carolina, your closing attorney's schedule. (See how the process works for the full timeline.)

Float-down options

Some lenders offer a float-down: if rates drop meaningfully after you lock, you get one chance to reset to the better market. It sounds like having your cake and eating it too, and sometimes it nearly is — but float-downs typically have conditions: the improvement must clear a minimum threshold, there may be a cost built into the pricing, and it's usually a one-time option. A float-down is a nice feature when available; it's not a reason to pick a lender whose base pricing is worse.

The asymmetry of regret

Here's the frame we find most useful. Imagine two futures after you lock:

• Rates fall. You feel a sting. But you still have the payment you already decided you could afford, on the loan you already decided made sense. Nothing about your life changed. And if the drop is large enough, refinancing remains open to you.
• Rates rise. If you floated, your payment is now higher — possibly for decades. On a purchase, there's a sharper risk most people never hear about: if rates rise enough while you float, your debt-to-income ratio can drift past program limits, and a loan that qualified can stop qualifying. Rising rates don't just cost money; they can cost the approval itself. (Here's how DTI works.)

The downside of locking is regret. The downside of floating can be a different house, or no house. Those aren't symmetrical risks, and treating them as a coin flip misprices the coin.

Why timing the market rarely beats locking when the numbers work

The people who trade mortgage-backed securities for a living — with terminals, models, and decades of data — get direction wrong constantly. That's not an insult; it's what an efficient market does. A client floating a lock is making the same bet with higher stakes and less information.

So we suggest a different question. Not "will rates be lower next week?" — nobody knows — but "do the numbers work today?" If the payment fits your budget, the loan fits your plan, and the pricing is competitive for your scenario, locking converts a good decision into a certain one. If rates fall later, that's what refinancing is for. If they rise, you're already safe.

Watching the market is part of our job, and we're glad to share what we see on any given day — which reports are coming, whether pricing has been volatile. What we won't do is pretend certainty we don't have, or press you to lock to close a file. The decision is yours; our role is to make sure it's an informed one.

A practical sequence

1. Get your scenario priced accurately — score, down payment, property type — so the quote is real. (Getting pre-approved does exactly this.)
2. Confirm the payment works at today's rate, not a hoped-for one.
3. Choose a lock window that covers your realistic closing date with room to spare.
4. Lock, and let the market be interesting instead of stressful.

You can see live pricing anytime with the rate widget on our home page — no personal information required. When the numbers work for you, we'll be ready.