Hybrid ARMs

A hybrid ARM features an interest rate that is fixed for an initial period of time, then floats thereafter. The "hybrid" refers to the ARM's blend of fixed-rate and adjustable-rate characteristics. Hybrid ARMs are referred to by their initial fixed-rate and adjustable-rate periods, for example 3/1 for an ARM with a 3-year fixed interest-rate period and subsequent 1-year interest-rate adjustment periods. The date that a hybrid ARM shifts from a fixed-rate payment schedule to an adjusting payment schedule is known as the reset date. After the reset date, a hybrid ARM floats at a margin over a specified index just like any ordinary ARM.[3]
The popularity of hybrid ARMs has significantly increased in recent years. In 1998, the percentage of hybrids relative to 30-year fixed-rate mortgages was less than 2%; within 6 years, this increased to 27.5%.[3]
Like other ARMs, hybrid ARMs transfer some interest-rate risk from the lender to the borrower, thus allowing the lender to offer a lower note rate in many interest-rate environments.