Adjustable-rate mortgages (ARMs) remain a minority of total agency originations, but they have reemerged in 2026. This time, independent mortgage banks (IMBs) and more leveraged borrowers are driving a rise in market share, according to Polygon Research.

The analysis, updated Monday by Polygon founder and CEO Val Buresch, found that ARMs rose to 3.34% of agency loans through the first six months of 2026, up from 0.31% during the same period in 2021. A total of 39,166 ARM loans were originated from January to May 2026, compared to 35,591 in all of 2021.

The report relied on Fannie details ⇒