From Vimal Gor at MT:
September began as a month of clear trends, trends that had continued from August and seemed, if anything, to be gaining more momentum. Among those trends were a weaker US Dollar and lower US yields, spurred early in the month by various Fed speakers warning of the dangers of hiking in the face of lower-than-expected inflation. Coupled with a lack of explicit concern from the ECB meeting regarding the strength of the Euro, EURUSD enjoyed another leg of strength taking the pair to a new high of above 1.20 during the month.
Various events over the course of the month have put those trends into question. Among them is the US tax plan, around which there continues to be much uncertainty, and it seems to have been left deliberately ambiguous to allow maximum room for negotiation. Nevertheless, there is enormous pressure from both sides to get something done now that the midterms are coming into view.