US mortgage rates hit highest since October as war keeps bond yields up, MBA says

The 30-year fixed mortgage rate rose 13 bps to 6.43% in the week ended March 20, its largest weekly increase in 11 months and up ~34 bps since the U.S./Israel strikes began. MBA applications index fell 10.5% to 310.7, with refinance applications down ~14.6% and purchase applications down 5.4%. The 10-year Treasury yield climbed from 3.96% before the attacks to 4.39% (~43 bps) as oil surged from about $75 to ~$100/bbl, and markets have repriced the probability of Fed rate cuts this year downward.

Analysis

The shock to oil supply is acting through two rate channels simultaneously: a direct inflationary impulse that lifts nominal yields and a convexity-driven feedback where dealers and mortgage originators re-hedge MBS duration aggressively, widening spreads between pass-throughs and Treasuries. That second-order hedging effect is more damaging to originator economics than the headline rate move because it increases funding/hedging costs immediately while the revenue from new loans drops with a lag.

Housing demand is likely to compress further over the next 1–3 quarters as affordability stress cascades from higher financing costs into fewer listings, longer time-on-market and higher cancellation rates for contracts in the pipeline. Inventories may temporarily stabilize, but margin compression will show up in homebuilder guidance and supplier order-books before raw-material prices adjust, creating a multi-quarter earnings negative for builders and their smaller contractors.

Mortgage REITs, servicers and regional banks carry the largest convex exposure: agency spread widening and MSR markdowns can hit NAVs and capital ratios quickly because these businesses fund long assets with short liabilities. Conversely, commodity producers and inflation-linked assets benefit from the same shock, creating a persistent sectoral divergence until either oil risk is resolved or the Fed credibly re-anchors inflation expectations.

Key catalysts to watch are geopolitical de-escalation (fast reversal risk within days), coordinated SPR releases or OPEC adjustments (weeks), and sequential housing datapoints—new home sales, pending sales and bank pipeline metrics—over 1–3 months. A re-pricing of Fed cut expectations would blunt the move; monitor real yields, dealer MBS positioning and servicer advance financing spreads for early signs of reversal.

Key Decisions for Investors

• Pair trade (3–6 months): Short PHM (PulteGroup) 2% NAV / Long XOM (Exxon) 2% NAV. Rationale: asymmetric downside in builders from margin compression vs upside for integrated oil on sustained oil-risk premium. Risk management: tighten stop on PHM at +8% adverse move; take-profit if PHM reports two consecutive negative guidance revisions or Brent-equivalent falls >20% from current levels. Target reward 2.5–3x risk if housing guidance deteriorates.
• Mortgage convexity hedge (1–4 months): Buy 20% OTM puts on AGNC or NLY expiring 3–6 months (size 0.75–1% NAV) to protect against NAV compression and dividend cuts. If prefer cash short, take a small short position in NLY (1% NAV) instead. R/R: tail protection cost expected <1% NAV; payoff >3x if spreads widen materially.
• Rates directional (days–3 months): Short TLT (or buy 10yr futures to express long yields) sized to risk 1–1.5% NAV. Entry on any yield pullback rallies; stop if 10yr real yields compress by >35bp on Fed-speak or oil de-escalation. R/R: discretionary—large payoff if the oil/reflation dynamic persists; principal loss if geopolitical risk eases rapidly.
• Inflation hedge & sector swap (3–12 months): Overweight TIPs ETF (e.g., TIP) 1–2% NAV and long XLE 2% NAV while underweight XHB (homebuilding ETF) 2% NAV. This reduces portfolio duration and captures a sector divergence if inflation remains sticky. Rebalance if TIP breakevens compress by >25bp or if homebuilder forward orders stabilize across two quarters.