Holdings of SPDR Gold Trust GLD, the world's largest gold-backed exchange-traded fund, fell by 0.29 tonnes on Tuesday. By Eileen Soreng Oct 19 (Reuters) - Gold inched lower on Wednesday as the dollar gained some ground, while the U.S. Federal Reserve's commitment to tightening its monetary policy also weighed on zero-yield bullion's appeal. While gold is generally seen as a hedge against inflation, higher interest rates increase the opportunity cost of holding non-yielding bullion.