The first action was larger than markets expected at the time – indeed, quotes from the federal funds futures market as well as survey data indicated that most investors had anticipated a cut of only 25 basis points in the target federal funds rate ahead of that meeting.
As reported in the minutes, the Federal Open Market Committee (FOMC) judged that a policy easing of 50 basis points was appropriate to help offset the effects of tighter financial conditions on the economic outlook.