Equities in the U.S. and Asia fell in tandem after the U.S. Federal Reserve failed to offer new monetary stimulus on Wednesday. While the outcome was largely expected, some observers say it’s not so much what the Fed could have done, but what it should have said.

Chairman of the Federal Reserve Ben Bernanke speaks at the Federal Deposit Insurance Corporation headquarters, on February 16, 2012 in Arlington, Virgina.

Although Fed officials said the U.S. economy had "decelerated somewhat," they also held back on fresh measures, dashing expectations among some investors and sending risk assets such as stocks and commodities lower.