GBP/USD was testing the prominent resistance level at 1.6120 which is a previous low in August & 61.8% Fibonacci level.
Friday's daily candlestick was a short body candlestick which indicates weakness of the bulls at this important junction of the chart which was followed by the heavy bearish reaction today.
Today's daily candlestick is very bearish till now but we need to see the daily closure to have the confirmation.
As we see on the 4H chart, we had a congestion zone (supply) at our resistance area 1.6070-1.6150.
This consolidation was followed by a very bearish 4H engulfing candlestick indicating the strength of bears there.
It's important to note that the pair managed to close below the last swing high at 1.6030 indicating signs for structural failure of the ongoing uptrend.
Now it's recommended to go short either at retest of the supply zone at 1.6070-1.6150 or when we have bearish breakout of the marked bullish channel.
SL should be 4H closure again inside the broken channel.
Profits should be taken every 50 pips till 1.5800.