The dollar firmed as commodities sold off, sending the dollar index up 0.5 percent to just above 96. Platinum plunged more than 3.5 percent in its worse sell-off since January, while gold lost about 2 percent to $1,223 per troy ounce.
Both the Mexican peso and Canadian dollar were down more than 1 percent against the greenback. Oil was also weaker. West Texas Intermediate futures lost 4 percent, closing below the key $40 level — at $39.79 per barrel.
The dollar index has been moving higher since March 18, two days after the Fed met and sent a seemingly dovish message to markets. But more recent hawkish comments from Fed officials have helped give the dollar a lift in a fairly dramatic move against a basket of currencies as traders reassess interest rate expectations.