Not much from a consumer’s standpoint is pegged directly to the fed rate. At least some ARMs are pegged to a bank’s prime rate, however, which tends to move with the fed rate. It seems to be a lot less common for ARMs to be tied to prime though – as you indicated a lot of them are based on Libor or even treasury rates. I probably should have made that more clear above.

Though it goes against every fiber of my being to link to an article on AOL (it’s really written by the Wall Street Journal, but I think their site requires a subscription), here’s a pretty good summary of what benefits may flow from yesterday’s cut: AOL Article