The Dow Jones Industrial Average has topped the 10,000 mark for the first time in a year.
World markets were boosted by the news after JPMorgan Chase reported a better than expected profit of $3.6 billion for the July-September quarter.
The BBC reported the Dow briefly reached 10,000.07 - its highest level since October 2008, before falling back to 9,987.75.
The index later closed 144.8 points higher at 10,015.86 - its highest level since October 2008.
European markets also closed higher on Wednesday. The FTSE in London was up 2% to close at 5,256.1, the CAC-40 index in Paris was up 2.1% and the DAX in Frankfurt was up 2.4%.
Banking stocks were among the top risers, with Barclays up 6.6%, Societe Generale climbing 4.7% and Deutsche Bank adding 4.2%.
Earlier, in Tokyo, the Nikkei Index was down 16 points to 10,060.
The Australian 200 Index was up 45 points to 4831 on Wednesday.
The NZX50 was up 17 points to close at 3186 on turnover of $87 million.
At 8.30am, the New Zealand dollar was trading at 73.86 US cents, 80.89 Australian cents, 46.23 pence, 66.03 yen and 0.4952 euro. The Trade Weighted Index was at 66.22.
Oil & gold still rising
Brent crude oil rose to $US73.88 per barrel, boosted by a weak US dollar and optimism about a global economic rebound that will lead to higher energy demand.
Gold was trading at $US1062.70 per ounce.