Are you ready if there’s a sudden boom?
The days of "everybody has a 3% mortgage" are numbered. Millions of pandemic-era ultra-low-rate loans have already been paid off, sold, or refinanced away — and the borrowers left holding today's higher rates make up a fast-growing, genuinely refinanceable pool. That shift is rewriting the risk math for mortgage-backed securities investors, and it has direct implications for originators and brokers racing to be first in line when the next rate dip arrives.
At the close of 2021, close to 15 million active first-lien mortgages in the US carried rates below 3%, according to data from Intercontinental Exchange (ICE) cited in a September 14 Wall Street Journal analysis. By this July, that number had slipped under 12 million. Meanwhile, the share of unpaid mortgage principal sitting at 5% or higher has climbed from roughly 10% at the end of 2022 to more than 40% today.
The originator-side evidence is already showing up
That shift isn't just theoretical — it's visible in weekly application data. The 30-year fixed rate stood at 6.78% for the week ending August 21, according to the Mortgage Bankers Association's Weekly Applications Survey, and the refinance share of total applications ticked up slightly to 42%, even as overall refinance volume ran below year-ago levels. "Mortgage rates and applications changed little last week, with just a slight increase in refinances for conventional and VA loans," said Joel Kan, MBA's vice president and deputy chief economist, adding that borrowers with larger loan sizes remain reluctant to refinance at current rate levels.
That's a market sitting in a holding pattern — but one where a much bigger share of borrowers than a few years ago would actually move if rates dropped meaningfully. It's a dynamic brokers are already competing over: UWM's incentive push toward VA and FHA refinances raised eyebrows among mortgage-backed securities investors last year, a reminder that origination-side pricing decisions and MBS investor concerns are more connected than most loan officers might assume.
Why bond investors are watching prepayment speeds again
Mortgage bonds, particularly those pooled by Fannie Mae and Freddie Mac, have historically paid investors a premium over Treasurys specifically because of prepayment risk, the chance a borrower pays off a loan early, usually by refinancing, and hands the investor their principal back sooner than expected. The current coupon rate for 30-year agency mortgage bonds sits around 5.8%, compared with just under 5% for 10-year Treasurys.
That premium barely mattered while rates were near two-decade highs; nobody holding a 3% mortgage was refinancing into a 7% one. But with average 30-year rates hovering in the high-6% range, according to Freddie Mac's weekly Primary Mortgage Market Survey, a growing share of borrowers now hold rates close enough to today's market that a meaningful drop could set off a genuine wave of payoffs.
Harley Bassman, the veteran strategist who created the MOVE index and writes under the banner "The Convexity Maven," put the trade-off bluntly in the Journal's report: mortgage bonds let investors "get more yield than Treasurys," but the cost is losing more when rates climb and gaining less when they fall.
Read next: Ackman: Prepayment penalties on Fannie, Freddie mortgages could bring rates lower
Bigger loans, more nonbank servicing, and the AI wildcard
A few forces could make prepayments move faster than models expect. Walt Schmidt, mortgage strategist at FHN Financial, has pointed out that today's borrowers carry larger average loan balances, hold stronger credit profiles, and are increasingly serviced by nonbank companies which are firms whose business model depends on refinancing their own customers as often as possible.
FHN strategists warned in a July note that the market may be underpricing the risk of faster-than-expected payoff speeds.
Read next: "Lock-in effect" keeps homeowners stuck, stalls housing recovery
Technology compounds that risk. Morgan Stanley strategists have flagged that artificial intelligence tools built to automate and speed up refinancing could make borrowers quicker to act than historical prepayment models assume, potentially catching bond investors off guard on timing. That mirrors what's already happening on the origination side, where large nonbank lenders and servicers are rolling out AI-driven recapture and refinance-trigger tools designed to shave weeks off a process that has traditionally moved slowly, which is the kind of friction reduction that could compress the gap between a rate drop and a wave of payoffs, and intensify the fight between brokers and big servicers over who reaches eligible borrowers first.
The bigger picture: prepayment is back on the agenda in Washington, too
This isn't only a Wall Street conversation. Billionaire investor Bill Ackman recently reignited debate over whether Fannie Mae and Freddie Mac should offer new loans with prepayment penalties, arguing that the free option to refinance at any time is exactly why MBS investors demand extra yield in the first place. It's also tied to the broader inventory story: ICE's own Mortgage Monitor research has shown how the rate "lock-in effect" has kept homeowners glued to their existing loans and starved the market of listings. As that effect eases, the same shift loosening housing supply is reshaping prepayment risk in the bond market.
What it means for brokers and lenders
A larger share of the market now sits within realistic refinance range, meaning the next meaningful rate drop, even a modest one, could trigger a faster, larger wave of applications than many shops have staffed or systemized for. It also raises the stakes in the recapture battle between independent brokers and large bank or nonbank servicers already investing in predictive technology to reach eligible borrowers first.
For now, with long-term yields elevated and the Federal Reserve leaning toward caution rather than cuts, a sudden refinance boom looks unlikely. But the warnings from bond strategists are less about tomorrow than about positioning for whenever the next down-cycle in rates arrives potentially, some strategists have suggested, tied to a cooling in the artificial-intelligence investment boom that has helped keep long-term yields elevated. When that moment comes, mortgage bond holders and the brokers competing for refinance business alike may find the market moves faster than they expected.
Read next: UWM's broker incentive raises concerns for mortgage-backed securities investors
