Stocks experienced wild swings, with traders overwhelmed by the flood of headlines following the Federal Reserve's decision and Jerome Powell's press conference, which signaled at least two things: policy will remain aggressively tight, and a soft landing appears increasingly unlikely.

The S&P 500 finished near session lows, extending its drop from a January record to more than 20%. Following the Fed announcement, the index struggled to find direction, rising as much as 1.3% at one point. The two-year interest rate surpassed 4% for the first time since 2007. The dollar gained.

Fed Chair Jerome Powell said officials were "strongly committed" to containing inflation after raising interest rates by 75 basis points for the third time in a row and signaling a similar move in November. Powell's main message was that officials were "dedicated" to bringing inflation down to the Fed's 2% target, and that "we will keep at it until the job is done." The phrase was inspired by the title of former Federal Reserve Chairman Paul Volcker's memoir, "keeping at it."