GBPUSD on the D1timeframe chart at 2017.08.17 00:00 is now signaling: a reversal candle (up) (a potential long) . This signal alone is a possible buy signal. But always check the logic of the idea from the current chart action. Also, look for a retrace to 40%, 50% or 60% of the signal candle if considering an entry for a better price and higher reward to risk ratio.
The chart is attached.