Mortgage rates moved higher across the board during the week of March 21, 2026. All three major loan types tracked by Wirly posted increases, pushing borrowing costs further from recent lows. If you are watching the market to decide when to refinance, this week’s data offers some useful signals worth understanding.
Rates as of 2026-03-26, sourced from Federal Reserve Economic Data (FRED). Previous week data as of 2026-03-19. Wirly is an educational comparison platform and is not a lender or mortgage broker.
This Week’s Rates
Here is a snapshot of where mortgage rates landed for the week ending March 21, 2026:
- 30-Year Fixed: 6.38% – up 0.16% from the previous week
- 15-Year Fixed: 5.75% – up 0.21% from the previous week
- 5/1 Adjustable-Rate Mortgage (ARM): 6.06% – up 0.11% from the previous week
The 15-year fixed saw the largest single-week jump of the three, rising 0.21%. That is a notable move for a product that many refinancers favor because of its lower rate and faster payoff timeline. The 30-year fixed climbed 0.16% to sit at 6.38%, while the 5/1 ARM posted the smallest gain at 0.11%, landing at 6.06%.
It is worth noting that the 5/1 ARM rate of 6.06% is currently higher than the 30-year fixed rate of 6.38% by a smaller margin than many borrowers might expect. Typically, ARMs carry lower initial rates than fixed-rate loans, so the narrow gap between the 5/1 ARM and the 30-year fixed this week is something refinancers should factor into their comparisons.
Why Rates Moved
To understand why mortgage rates went up this week, it helps to look at two key economic benchmarks: the Federal Funds Rate and the 10-Year Treasury yield.
The Federal Funds Rate
The Federal Funds Rate currently sits at 3.64%. This is the interest rate at which banks lend money to each other overnight, and it is set by the Federal Reserve. While the Fed does not directly set mortgage rates, its policy decisions influence borrowing costs throughout the economy. A Fed Funds Rate of 3.64% signals that monetary policy remains in a moderately restrictive stance, which tends to put upward pressure on consumer lending rates, including mortgages.
The 10-Year Treasury Yield
The 10-Year Treasury yield is arguably the single most important benchmark for 30-year fixed mortgage rates. As of this week, the 10-Year Treasury yield stands at 4.42%. Mortgage lenders typically price 30-year fixed loans at a spread above this yield to account for the added risk of lending over a long period. With the 30-year fixed at 6.38% and the 10-Year Treasury at 4.42%, that spread is approximately 1.96 percentage points, which is within the range that has been common in recent years.
When Treasury yields rise, mortgage rates tend to follow. If bond investors are demanding higher returns on government debt, lenders will generally require higher returns on mortgage loans as well. This relationship helps explain why all three mortgage products moved upward together this week.
What This Means for Refinancers
For homeowners considering a refinance, a week of rising rates is not necessarily a reason to panic, but it is a reason to pay close attention.
If you currently hold a mortgage at a rate well above 6.38%, refinancing into a new 30-year fixed could still reduce your monthly payment. However, the math becomes tighter as rates climb. A refinance that made strong financial sense at a 6.00% rate may offer less benefit at 6.38%.
For homeowners interested in paying off their loan faster, the 15-year fixed at 5.75% is still lower than the 30-year fixed rate. Switching from a 30-year loan at a higher rate to a 15-year at 5.75% could potentially lower your interest costs significantly over time, though your monthly payment would likely be higher since you are paying off the same principal in half the time.
The 5/1 ARM at 6.06% may appeal to borrowers who plan to sell or refinance again within five years, since adjustable-rate loans carry initial fixed periods. However, with the 5/1 ARM rate sitting close to the 30-year fixed rate of 6.38%, the typical advantage of choosing an ARM is narrower this week than it might be in other rate environments. Use our refinance calculator to run your own numbers and see which loan type could make the most sense for your situation.
Should You Lock or Wait?
This is the question most borrowers are wrestling with, and there is no single right answer. Here is a balanced look at both sides.
The Case for Locking Now
- Rates have risen three weeks in a row based on available data, and there is no guarantee the trend will reverse soon.
- With the 10-Year Treasury yield at 4.42%, there could be continued upward pressure on mortgage rates if yields stay elevated.
- Locking in at 6.38% on a 30-year fixed or 5.75% on a 15-year fixed secures a known cost and removes the uncertainty of waiting.
The Case for Waiting
- Economic conditions can shift quickly. If inflation data softens or labor market signals weaken, Treasury yields may fall and mortgage rates could follow.
- The Fed Funds Rate at 3.64% may suggest there is room for policy adjustments over time, which historically has tended to influence longer-term borrowing costs.
- Waiting may make sense if your current rate is only modestly higher than today’s market rates and the savings from refinancing would be limited.
Ultimately, the decision to lock or wait depends on your personal financial situation, how long you plan to stay in your home, and your tolerance for rate movement. A rate lock removes risk but also removes the chance to benefit if rates fall. Waiting preserves flexibility but carries the possibility that rates move higher. Neither choice is without tradeoffs.
Bottom Line
The week of March 21, 2026 brought higher mortgage rates across all three major loan products. The 30-year fixed rose to 6.38%, the 15-year fixed climbed to 5.75%, and the 5/1 ARM edged up to 6.06%. The broader economic backdrop, including a Fed Funds Rate of 3.64% and a 10-Year Treasury yield of 4.42%, helps explain why rates are at their current levels.
For homeowners considering a refinance, the key step is to run your own numbers. Visit our refinance calculator to estimate your potential savings based on your current loan balance, rate, and remaining term. When you are ready to compare options, our guide to the best refinance lenders can help you find lenders offering competitive rates and terms.
Staying informed is the foundation of a smart refinance decision. Check back each week for updated rate data and analysis.