Well, that was confusing. There were no news items that dropped the markets in the last 45 minutes of trading. Instead, traders seemed to talk themselves into a belief that the Fed was going to be more hawkish than its own statement seemed to indicate.
Stocks were modestly higher all day until the minutes from the Federal Reserve's January meeting came out at 2 p.m. ET. Traders liked what they heard: The Fed said there were few signs of a broad-based increase in wage growth.
Traders have been worried that inflation is picking up, and that higher rates would kill the rally, so the Fed saying it's not too worried was greeted as a positive sign, and bond yields initially dropped.
But then it all turned. Bond yields, which move opposite price, moved back up from about 2.91 percent on the 10-year to over 2.95 percent. And predictably, the stock market's rally fizzled.