The Payment Shock Wave: How 2021-2023 ARM Borrowers Face $2,500 Monthly Increases (And What It Means for Greater Boston Real Estate)

Between 2021-2023, ARM market share surged from 3% to 15% as buyers used adjustable-rate mortgages to afford homes during the rate spike. Now these loans are resetting from 3-4% teaser rates to 7-8%, creating payment shocks of $1,200-$3,800/year for jumbo borrowers. This won't cause a 2008-style crash—these are prime borrowers with equity—but it's freezing market liquidity, suppressing home renovations, and creating localized distress in Florida condos and speculative markets like Austin.