GBP/USD is unlikely to move far Wednesday ahead of the announcement on US monetary policy by the Federal Reserve at 1900 UK time (1800 GMT) and its press conference at 1930, both after the European markets have closed.
However, the strength of the pair persisted Tuesday, with GBP/USD moving above both the 200-day moving average and trendline resistance from the upper boundary of a falling channel in place since June 23. Note though that there is resistance too from another longer-term trendline in place since June 1, around 1.3910, and that could at least slow down any further gains.