Fed Rate-Hike Expectations Trigger Historic Exodus From Mortgage-Backed Securities
TREE NEWS reports: Investors have been pulling money out of US mortgage-backed securities (MBS) funds at a pace rarely seen in recent history. Over the past three weeks, weekly outflows have ranked among the seven largest since early 2021, as surging bond yields pushed investors to reduce exposure to rate-sensitive assets.
The selloff has left its mark on performance: a benchmark US mortgage-backed securities index posted its second-worst monthly return on record in September. The trigger was a sharp rise in Treasury yields, driven by spiking oil prices, resurgent inflation worries and growing expectations that the Federal Reserve will keep tightening monetary policy.
Why MBS Are So Sensitive to Rate Moves
Mortgage-backed securities sit at the intersection of the housing market and the broader cost of credit, which makes them unusually vulnerable to abrupt moves in bond yields. When rates climb, homeowners tend to stop refinancing their mortgages, leaving investors holding lower-yielding securities for longer than they had anticipated. That extension of duration amplifies losses in a rising-rate environment, and it helps explain why the recent yield surge translated so quickly into forced selling and fund redemptions.
Strategist Erica Adelberg noted that Fed tightening and a flattening yield curve could further erode demand from banks, which have long been among the most important buyers of MBS. A flatter curve compresses the spread banks earn on their holdings, while tighter policy raises their funding costs and ties up capital — a combination that makes mortgage bonds less attractive on bank balance sheets.
Supply Could Offer Some Relief
There is a silver lining. As mortgage rates climb to their highest level since 2023, refinancing activity and home-purchase demand are being suppressed, which should slow the growth of house prices and loan balances. That dynamic is expected to push MBS supply onto a downward trend through the end of the year, easing some of the pressure on the market.
Still, the episode carries broader implications. MBS are a key transmission channel for monetary policy into household borrowing costs, and their weakness signals that higher-for-longer rates are being priced in across fixed income. For mortgage borrowers, that means elevated loan rates are likely to persist; for investors, it points to continued volatility in duration-heavy assets.
The Forward View
The path ahead hinges on the inflation data and the Fed’s next moves. If oil prices stay elevated and inflation proves sticky, MBS funds could see further outflows and bank demand may keep fading. Conversely, any sign that the tightening cycle is near its end could stabilize yields and draw yield-hungry buyers back into the market. For now, the market is trading on one assumption: rates are not coming down soon.
