What it means
The best-known use is the mortgage rate lock. A lender agrees to hold an interest rate for a set time, commonly 30, 45 or 60 days, while the loan is processed.
If market rates rise in that window, the borrower is protected, and if they fall, the borrower may be stuck with the higher rate unless the lender offers a float-down option. In investments, a lock period is the time during which money cannot be withdrawn.
Hedge funds, private equity funds, term deposits and some staking arrangements in digital assets all use periods when investors cannot redeem. The restriction lets the manager invest in assets that cannot be sold quickly without a loss.
The length of a lock period affects the price. Longer locks usually come with higher returns or lower fees, because the investor gives up flexibility.
Lenders also charge for long rate locks, since they carry the risk of rates moving against them during the period. Breaking a lock can trigger penalties.
A term deposit may charge a loss of interest, a fund may charge a redemption fee, and a rate lock that expires before closing may need to be extended for a fee. It is wise to check the exact dates and what happens if closing is delayed.
Different from a lock period is a lockup period after a share offering, which restricts insiders from selling, and a vesting period for employee shares. All share the idea of a time restriction, but the rules and reasons differ, so always check the document that sets the lock.
For a borrower, the practical question is how long the process will take. Add a margin of a week or two to the expected closing date, since delays in valuations, paperwork and approvals are common.
A slightly longer lock costs a little more but avoids the risk of paying a higher rate or an extension fee.
In practice
Real-world examples.
Example
A couple agree to buy a home and lock their mortgage rate for 60 days. Rates rise during the period, but their rate does not change. Closing takes 55 days because of a delay in the survey. The 60-day lock covers the gap with five days to spare.
Example
An investor puts $100,000 into a private credit fund with a two-year lock period. He cannot redeem during the first two years, and the fund pays a higher yield in exchange. He plans his cash needs so he does not need the money. He keeps six months of expenses in a separate savings account for emergencies.
Example
A company places $2,000,000 in a 12-month term deposit with a bank. The deposit pays a better rate than an instant-access account. The treasurer notes the maturity date so the cash is ready for a tax payment. The deposit earns interest the whole time, but the money cannot be touched early without a penalty.
Formula
Calculation
Extra interest in the first year = Loan amount x (Market rate at closing - Locked rate)
A borrower locks a $300,000 mortgage at 6.0% for 45 days. By closing, the market rate for the same loan has moved to 6.5%. Because of the lock, the borrower still pays 6.0%, which saves a difference of 0.5%. The saving in the first year is $300,000 x 0.005 = $1,500 of interest. If closing is delayed and the lender charges 0.25% of the loan to extend the lock, the fee is $300,000 x 0.0025 = $750, which is still less than the extra interest.Case study
Seen in the real world.
Larkspur Holdings is an illustrative, fictional company that agreed to refinance a $5,000,000 property loan. The lender offered a 30-day rate lock for free and a 90-day lock for a fee of 0.2%.
The finance director estimated the closing would take about six weeks because of a legal review. She chose the 90-day option at a small cost rather than the free 30-day lock, which would have expired before completion.
The review did take six weeks, and market rates rose by 0.4% in the meantime. On $5,000,000, that would have cost an extra $20,000 a year in interest. The lock fee of about $10,000 was a sensible price for certainty. She noted the lesson for future refinancing projects.
Watch out
Common mistakes.
- Choosing a lock period shorter than the expected closing time, so the lock expires and the rate floats.
- Assuming a rate lock is a guarantee of the loan, when approval and conditions still apply.
- Putting money into a locked investment that may be needed for an emergency.
Questions
People also ask.
How long is a typical mortgage rate lock?
Often 30 to 60 days, though longer locks are available for a fee, depending on the lender and loan type, and a longer lock usually costs more.
Can I get out of a lock period early?
Sometimes, usually with a penalty, so check the terms in advance.
What is a float-down option?
It lets a borrower take a lower rate if market rates fall during the lock, usually for an extra cost.
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