GBP/USD is declining through a short-term trend-line. Lower lows suggest a downside momentum. Hourly resistance can be found at 1.5437 (27/05/2015 high) and supports is given at 1.5261 (28/05/2015 low).
In the longer term, the technical structure looks like a recovery bottom whose maximum upside potential is given by the strong resistance at 1.6189 (Fibo 61% entrancement).