Funds lifted bets on rising commodity prices to a six-week high after traders snapped up raw materials as alternative assets amid the escalating US debt crisis. Speculators raised their net-long position in 18 commodities by 10,063 futures and options contracts to 1.27 million in the week ended July 26, government data compiled by Bloomberg show. That\'s the highest since June 14. Silver holdings rose for a fourth straight week, and bullish sugar bets climbed to the highest since February 2010.