One leading expert said: 'The potential for a squeeze is huge.' Some say that a rise to $330 would trigger more 'margin calls', forcing gold bears to put up more funds. Such warnings have been heard before, but the gold market, though global, is relatively small and can easily be swamped by huge derivative trades. Some estimate the 'short' position at 1,500 to 3,000 tonnes - six months' to a year's output.