The average US 30-year fixed mortgage rate for conforming loans of $806,500 or less climbed to 6.43% for the week ending March 20, 2026, its highest level since early October and the third straight weekly increase. The surge weighed heavily on borrowing activity, with total mortgage applications crashing 10.5% after a 10.9% drop the previous week. Refinancing activity led the decline, plunging 14.6%, while purchase applications fell 5.4%, signaling mounting affordability challenges for homebuyers.