Being support by 1.6431, GBPUSD rebounded from 1.6451, suggesting that a cycle bottom is being formed on 4-hour. Further rise would likely be seen in a couple of days, and target is at 1.6745 previous high. However, a breakdown below 1.6431 support will indicate that the uptrend from 1.5936 (Mar 28 low) has completed at 1.6745 already, then the following downward movement could bring price back to 1.6250 zone.