Updated July 18, 2026 — U.S. stocks finished Friday lower as a retreat in semiconductor shares deepened and the Iran conflict kept pressure on energy prices.

The S&P 500 fell 1 percent, the Dow Jones Industrial Average lost 406 points, or 0.8 percent, and the Nasdaq composite declined 1.4 percent. Nvidia fell 2.2 percent. The Philadelphia semiconductor index lost about 10 percent for the week, its largest weekly decline in more than a year, according to Reuters.

The chip index remained more than 60 percent higher for the year, so the week's losses do not by themselves establish a lasting reversal. They do show that highly valued AI-linked shares can move sharply when investors question future spending, take profits or reduce leveraged positions.

Oil's rise during the U.S.–Iran fighting added a separate inflation and earnings risk. The combination of higher energy costs and falling technology shares materially extends this story beyond the initial one-day market reaction reported earlier in the week.

Source: Associated Press — apnews.com source ↗

Source: Reuters — au.investing.com source ↗