After all the concern that the U.S. is debasing its currency,the dollar beat stocks, bonds and commodities for the first timesince May as investors sought refuge from slowing growth andEurope's sovereign-debt crisis.

The U.S. currency rose 6 percent in September, according toIntercontinentalExchange Inc.'s Dollar Index, beating returns of1.6 percent by Bank of America Merrill Lynch's U.S. Treasury MasterIndex. The MSCI All-Country World Index of stocks in 45 countrieslost 8.9 percent, the largest monthly drop since May 2010. Rawmaterials measured by the Standard & Poor's GSCI Total ReturnIndex of 24 commodities slid 12 percent.

Gains for the world's reserve currency show investor confidencein the nation's creditworthiness after Standard & Poor'sstripped the U.S. of its AAA rating two months ago. Even withRepublican leaders in Congress joining critics of Federal Reservestimulus measures, the currency bested all 16 of its most-tradedcounterparts in September for the first month in more than threeyears.