A quiet day on Wall Street yesterday turned into the worst sell-off in three months after a Federal Reserve official said he doubted the bank's effort to boost economic growth would work.

A quiet day on Wall Street turned into the worst sell-off in three months after a Federal Reserve official said he doubted the bank’s effort to boost economic growth would work.

Wall Street ended a fractious session slightly higher tonight after falling oil prices hurt energy stocks and overshadowed a stronger-than-expected productivity reading.