The Bureau of Economic Analysis has revised its estimate of U.S. Gross Domestic Product (GDP) growth for the second quarter of 2014 upwards to 4.2%. This figure represents an annualized rate and is an increase from the initial estimate of 4.0% released last month.

The upward revision primarily reflects stronger business investment and exports than previously estimated. Consumer spending, which accounts for a significant portion of the U.S. economy, also contributed to the improved growth figure.

Economists view this revision as a positive sign, indicating that the U.S. economy is gaining momentum after a slow start to the year. The stronger-than-expected growth in the second quarter could lead to further upward revisions in future GDP estimates.

Key factors contributing to the revised GDP growth include:

• Increased business investment in equipment and software
• Stronger export growth, particularly in goods
• Solid consumer spending on durable goods and services

While the revised GDP figure is encouraging, some economists caution that the pace of growth may not be sustainable in the long term. Factors such as global economic uncertainty and potential interest rate hikes by the Federal Reserve could weigh on future growth.