This abrupt move by the Fed betrays lack of knowledge of stock market psychology. Looking at how stocks are doing today you would not think that anything of interest has happened (no pun intended).

The stock market psychology works on "buy on rumor, sell on news" principle. This is the reason there was a significant rally yesterday, and stocks are in negative territory today.

What the Fed should have done is give signals that they are about to cut interest rates, then give stronger signals, then even stronger signals, then cut interest rate by 0.25% then repeat for the next 0.25%. Markets would have rallied multiple times for each good news signal.