As the harmonic patterns -- which are reversal patterns -- mentioned in this previous analysis completed, we started searching for an opportunity to sell. If a reversal pattern doesn't cause full reversal, it can cause at least a 30% retracement against the total length/move of the pattern.
Since we wanted to exit the sell position at the nearest target, which is 30% of ab, we looked at M30 timeframe to find an early opportunity. As soon as the widening triangle shown in the picture, was broken to the downside, we entered a sell position.
Risk: If the GBP/USD returns back to upside and an H4 candle will close above today's high made so far, exit the trade.