NEW YORK (MarketWatch) -- Gold futures tumbled 3.8% Thursday to below $710 an ounce as the U.S. dollar kept strengthening and as fund sale continued. Gold for December delivery lost $28.20 to $707 an ounce in early electronic trading. It fell to as low as $704 overnight. Gold has been fallen ten out of eleven sessions since Oct. 8 and has tumbled $200.