The Daily timeframe of the GBP USD is shown in this analysis with price action from ~ October 11, 2018 to current date captured using a bullish channel.
Extremes used to identify the width of the channel are ~1.38343 and 1.19602. Chart patterns nesting inside of one another are a common occurrence, and so it is in this case where a smaller bullish channel (tentative) identified with blue lines commenced from August 16, 2018 to Friday close (October 19,2018).
A break below ~1.27735 and especially below support in this region could result in a selloff of the GBP USD.
The minimum price expectation following price exiting the upside of the smaller channel at ~1.35761 is the upper limit of the channel at ~1.46537.