In the previous trade day, GBPUSD in M15 chart broke down the neckline and test the 23.6% of Fib retracement. It seems a short term rebound will occur and challenge the neckline level. If fail, the GBPUSD will continue the descending trend and finally test 1.21 level.
For the trading strategy, a sell limit can be placeed around 1.23-1.232 with stop loss 1.235-1.238 if the rebound occur, take profit target at 1.215-1.21, Market sell can be also considered if greater loss is affordable.