Most homebuyers don't hold their mortgage to term, whether due to selling or refinancing (like you). All things equal, an ARM will be priced lower than a longer

Most homebuyers don't hold their mortgage to term, whether due to selling or refinancing (like you). All things equal, an ARM will be priced lower than a longer-term FRM, so taking out the ARM with the intention to sell or refinance will mean lower guaranteed costs on the initial mortgage. They're basically a call option on rates during/after the initial fixed term. Even if rates go up a lot (like now), the pre-defined ratchet probably keeps them competitive relative to FRMs. Eventually, a weaker economy probably brings lower rates, especially combined with more equity and a shorter term. When 30-year FRM rates are 3%, though, take the fixed.