May 20 (Reuters) - The S&P 500 and the Nasdaq opened higher on Wednesday, lifted by a rebound in chip stocks ahead of Nvidia's ( NVDA ) quarterly earnings, which investors view as a crucial test of AI demand as they weighed concerns over elevated Treasury yields.

The Dow Jones Industrial Average fell 15.0 points, or 0.03%, at the open to 49348.83. The S&P 500 rose 15.6 points, or 0.21%, to 7369.19​, while the Nasdaq Composite rose 120.8 points, or 0.47%, to 25991.509.