GBP/USD is continuing to drift higher, tapping into 1.2670 in early Wednesday action thanks to a softening US Dollar, but broader market remains prone to risk shocks as investors fear a global growth slowdown, and Brexit continues to hang over the Sterling as an ever-present reminder that January is likely to unwind any gains seen in the interim.Wednesday brings a healthy smattering of UK data in the early London window, though most of the data readings land firmly in the mid-tier or lower categories; 09:30 GMT sees UK m/m Retail Price Index (forecast 0.1%, last 0.1%), m/m Producer Price Index - Output (forecast -0.1%, last 0.3%), and November's Consumer Price Index (forecast 0.2%, last 0.1%), all dropping simultaneously, but Sterling markets are likely to remain constrained as traders feel the pressure of continued Brexit headlines.