GBP/USD is the forex quote for the British Pound versus the US dollar. This pair is often called ‘cable’ by traders, as this references the first transatlantic cable that was set up to connect England and the United States, which was then used to transmit currency quotes between the two economies. This is one of the oldest FX pairs, and often stays liquid throughout the day. It can be especially volatile during the ‘crossover’ portion of the trading day, when banks and funds are trading in both Europe and the US. This usually lasts from around 8 AM ET – 11 AM ET.
Given the different nature of the US and British economies, there can often be divergence in economic data or prospects and this can create strong trending movements in the pair. If the British Pound is strong and the US dollar is weak, GBP/USD can be especially bullish, while the reverse is true for bearish scenarios, and this is why the pair is often a favored vehicle from professional traders.