GBPUSD’s downward movement from 1.6176 extends to as low as 1.5756. Initial resistance is located at the downward trend line on 4-hour chart, as long as the trend line resistance holds, the downtrend could be expected to continue, and next target would be at 1.5700 area. Key resistance is at 1.5900, only break above this level could signal completion of the downtrend.