GBPUSD broke above 1.6400 resistance, suggesting that the downward movement from 1.6668 had completed, and the pair is now in uptrend from 1.6252. Further rally could be expected, and next target would be at 1.6550 area. Support levels are at 1.6340 and 1.6252, only break below these levels could trigger another fall to 1.6150 zone.