Gold futures tumbled sharply on Thursday as the dollar rallied in the wake of the Federal Reserve’s bond-swap program and pessimistic economic data from China further damaged sentiment.

Gold for December delivery was off $74.20, or 4.1%, to $1,734.10 an ounce on the Comex division of the New York Mercantile Exchange, near session lows. It had traded as low as $1,731.20 an ounce earlier.

The iShares Silver Trust ETF  fell 7.3% and the SPDR Gold Trust ETF  fell 2.5%, while November gold futures slipped a more sharp 3.9%.