US stock indexes closed mixed on Monday as losses in megacap tech stocks offset optimism over progress in restoring energy supply from the Middle East. The S&P 500 fell 0.4%, while the Nasdaq 100 lost 0.2%. Alphabet dropped 5.2% after reports that another top AI researcher left for a rival, deepening concerns over its competitive position in artificial intelligence. Broadcom tumbled 4.7%, Amazon declined 4.4%, Microsoft lost 3.2% and Meta fell 2.7%. SpaceX plunged 16.4% after announcing a new bond sale. In contrast, Micron gained 6.8% after announcing a strategic agreement with Anthropic. Meanwhile, the Dow Jones rose 148 points after Iran said recent talks with the US made significant progress, with both sides aiming to reach a peace deal within two months. Energy prices extended losses on expectations of restored supply, while lingering expectations of a hawkish Federal Reserve following last week’s meeting kept pressure on Treasuries.