U.S. stocks rose Thursday, following stock markets around the world, after the G20 agreed to pledge more than $1 trillion in emergency aid and accounting changes were made in the way banks value the toxic assets now clogging their balance sheets.

Specifically, the lending power of the International Monetary Fund was boosted to around $750 billion while the IMF's reserve currency, known as special drawing rights (SDRs) were expanded by about $250 billion. Both measures were taken in an effort to help support poor countries.

Meanwhile, the Financial Accounting Standards Board voted to relax fair-value accounting rules, giving auditors more flexibility in valuing the toxic and illiquid assets now sitting on bank balance sheets. As a result, banks are less likely to take big write downs, which could potentially allow them to use more capital for lending. Critics argued that altering the rules could make their overall health less visible.

The dollar was firmly trading in risk-acceptance mode (lower vs. the better-yielders and higher on the yen) as stocks rallied nearly 4% on the day, highlighted by nearly a 3% decline to Australia's dollar. Oil was rallying 8% as stocks gained and the dollar declined while gold fell nearly 3%. Treasuries also were declining as traders moved away from safety and into riskier assets.