RBA surprises with rate hike, stocks drop and Aussie dollar rises.

Global shares fell ahead of the Federal Reserve's upcoming policy meeting, while the Australian dollar soared after the central bank stunned markets with a surprise interest-rate hike. Short-dated government bond yields shot up after the Treasury Department said it could run out of the cash it needs to pay its bills by early June. The Fed is expected to raise interest rates by a quarter of a point on Wednesday, but with so much anxiety around the tug-of-war over the government's debt limit, as well as the stability banking sector after the failure of a third U.S. lender in two months, money markets show investors think this will be the last hike.