The U.S. economy bounced back in a huge way in the second quarter, with the gross domestic product jumping by an annualized rate of 4 percent after a sharp drop in the first quarter.

The rise, reported by the Commerce Department's Bureau of Economic Analysis, trounced economists' expectations of 3 percent GDP growth. The quarterly report also found that the slowdown during the first three months of the year was not as steep as earlier believed. The final estimate for the first quarter was a decline of 2.1 percent, an improvement from the previous estimated drop of 2.9 percent.

The 4 percent leap in April-June is just an initial estimate, however, so it likely will be revised in the coming months.

Among the factors contributing to the expansion were increases in private inventory investment, exports, and state and local government spending, the government said.

A separate report released on Wednesday by the Commerce Department found that the economy grew faster than expected in the second half of 2013 and at the highest clip since 2003, The Wall Street Journal reported.

President Barack Obama is likely to trumpet the rosy economic news in a speech later Wednesday in Kansas City.