The American economy has grown at a faster pace than expected.
The world's biggest economy expanded at an annualised rate of 5.7% in the last three months of 2009 - its strongest showing in six years.
The improvement is due to companies buying more stock.
But consumer spending, which makes up the majority of economic activity, fell compared to the previous quarter.
Even with the rebound, Gross Domestic Product shrank by 2.4% in 2009 - the worst annual performance since 1946.