Investors worry that G20 limits on bankers' pay would hurt financial stocks.
The authorities have launched a pilot project allowing some trade in renminbi. It comes as top US and Chinese officials wrap up a summit on economic coordination Tuesday.
Five months into the economic crisis, experts predict a years-long recovery.
A stronger US currency reduces inflation pressures, but American exports could run into head winds.
War spending, trade deficits, and devaluation against foreign currencies weigh on the greenback.