GBP/USD remains in an uptrend from 1.2589. The pullback from 1.3125 could be treated as a correction of the uptrend. A deeper decline towards the bottom trend line of the price channel on its 4-hour chart is possible in a couple of days. As long as the channel support holds, the uptrend could be expected to resume, and another rise to test 1.3200 resistance is still possible. Key support is at 1.2811.  Only a breakdown below this level could signal completion of the uptrend.

GBPUSD 4-hour chart