All three major US stock indexes closed higher on Monday, with the Dow Jones and S&P 500 both reaching record highs. The Philadelphia Semiconductor Index soared more than 6%, driven by strong gains across optical communication and memory sectors. On the geopolitical front, easing tensions between the US and Iran contributed to a sharp decline in international oil prices.

Gains were broad-based, with the Dow Jones Industrial Average climbing 1.71% to 54,085.88 points, the S&P 500 rising 1.79% to 7,736.52 points, and the Nasdaq Composite advancing 2.59% to 26,584.99 points.

Semiconductor stocks rally

The Philadelphia Semiconductor Index surged 6.55% in a single day. Among individual stocks, Micron Technology jumped 7.62%, Advanced Micro Devices gained 7%, Intel soared over 10%, ARM surged more than 17%, SanDisk Corp. climbed over 10%, and SK hynix rose more than 8%.

Most large-cap technology stocks also advanced, with NVIDIA up over 2%, while Apple, Tesla, and Microsoft each gained more than 1%. Amazon bucked the trend, dropping over 2%.

Chinese stocks listed in the US were mixed. The Nasdaq Golden Dragon China Index edged down 0.35%. Alibaba rose 1.31%, while ZTO Express fell 2.56%.

Oil prices fall sharply

International oil prices posted steep losses. Brent crude futures plunged 6% to settle at $78.68 per barrel, falling below the $79 mark. West Texas Intermediate (WTI) crude dropped 6.47% to close at $75.14 per barrel.