It's amateur hour
Unless there's some news that I'm missing (and I don't think there is), this drop in the US dollar is all about sales into the London fix or the European close at month end.
These flows should have been handled sooner but someone was selling on the job and as a result, we're seeing a sharp drop in the US dollar against the euro, yen and pound.
The GBP/USD move is the largest, up to 1.4214 from 1.4175.
With London closed, it's not exactly a fix but it's 5 pm in Paris and Frankfurt so the idea is the same.