Feb 25 (Reuters) - The benchmark S&P 500 and the Nasdaq

had a subdued start on Tuesday as markets braced for the

potential impact of more stringent U.S. trade controls on

Beijing and awaited quarterly earnings from AI-chip leader

Nvidia.

The Dow Jones Industrial Average rose 48.5 points, or

0.11%, at the open to 43,509.74. The S&P 500 fell 0.5

points, or 0.01%, at the open to 5,982.73​, while the Nasdaq

Composite dropped 44.3 points, or 0.23%, to 19,242.608

at the opening bell.