U.S. stocks finished steeply lower on Wednesday, wiping out the prior day's gains and more, as the Federal Reserve opted to stick with its plan to continue to reduce its monthly bond purchases, now down to $65 billion, regardless of recent distress in emerging markets.

"Today's Fed decision to continue with tapering, despite the unfolding turmoil in emerging markets, suggests the Fed has a domestic policy compass firmly in hand. The Fed is sending a clear message that unless a much larger scale crisis emerges, do not expect the Fed to deviate from its current policy path," wrote Jonathan Lewis, chief investment officer at Samson Capital Advisors.