Dollar slips while stocks post September in decades

The dollar continued to slide this week, as market uncertainty and worries about intervention by Japan and the United States held the currency market hostage.

The dollar index, which gauges the greenback against a basket of currencies, retreated to a low of 78.1, a level not seen since February. That's down from 83.2 at the beginning of the month, and far below the June high above 88.

But it's not a huge surprise that September has been a lackluster month for the dollar. Hedge funds and other big money investors typically pour money into commodities following Labor Day, said Michael Woolfol, senior currency strategist at Bank of New York Mellon. That can take its toll on the U.S. currency, since commodities like gold, oil and grains are priced in dollars.