I'm away at the moment so finger it 100% on the pulse but as far as I can tell its about DXY and hawkish FOMC commentary overnight. Well when I say hawkish, I mean in line with their most recent guidance which the market had ruled a line through as BS. As I said a few days ago, if rates do actually go up then there are going to be a lot of traders caught with their pants down.
As for Bhp... you know what normally follows periods of high volatility.