A report that raised the possibility of the Bank of England extending its emergency bond purchase caused the dollar to reverse a gain and the pound to swing to a gain.
A change in risk sentiment caused US stock futures to soar and Asian equities markets to moderate losses.
According to the Financial Times story, the BOE informed bankers that its bond-buying scheme to prevent a crisis in UK pensions may continue after the deadline of October 14 passed.
This was in opposition to remarks made on Tuesday by the governor of the central bank, who urged investors to get ready for the program's termination this week.
The dollar was pushed back on Wednesday as market movements came to a halt, although equities in Australia and South Korea moved up.
Hong Kong's stock market remained negative.