US Dollar is a weighted average, see below. Mainly effected by the Euro at 57.6%, up a half percent, but the real driver overnight was the Brit Pound moving up over 2.5% due to the vote.

Euro (EUR), 57.6% weight
Japanese yen (JPY) 13.6% weight
Pound sterling (GBP), 11.9% weight
Canadian dollar (CAD), 9.1% weight
Swedish krona (SEK), 4.2% weight
Swiss franc (CHF) 3.6% weight

The USD dollar demise will be the kicker to the precious metals.......Look for a run