The euro rocketed to a two-month high of $1.29 and sterling jumped two cents to almost $1.54 after the Fed confessed that the US economy may not recover for five or six years. Far from winding down emergency stimulus, the bank may need a fresh blast of bond purchases or quantitative easing.
Usually the dollar serves as a safe haven whenever the world takes fright, and there was plenty of sobering news from China and other quarters on Thursday. Not this time. The US itself has become the problem.
"The worm is turning," said David Bloom, currency chief at HSBC. "We're in a world of rotating sovereign crises. The market seems to become obsessed with one idea at a time, then violently swings towards another. People thought the euro would break-up. Now we're moving into a new phase because we're hearing alarm bells of a US double dip."
