They exist. I have a 10/1 io, at which point it becomes a 20 year amortization with a floating rate. The bet was that inflation would eat the principal down and I probably wouldn't be in the house more than 10-12 years anyway
- You'll sell the house before 10 years
- Rates will go down and you can refinance
I'm in a more standard 10/1 ARM for similar reasons - the interest rate was lower and I felt it was a reasonable bet that we'd be able to refinance for a better rate (or worst case slightly worse rate) in the next 10 years.