U.S. equity futures fell Tuesday as rising Treasury yields pressured risk-sensitive assets at the start of September, a month with a historically weak reputation for the S&P 500. Semiconductor and artificial intelligence stocks including Sandisk, Marvell, Intel and Corning declined in premarket trading, while the VanEck Semiconductor ETF, Nvidia, AMD and Micron had previously each fallen more than 1%. Energy stocks advanced alongside oil prices as Middle East tensions persisted, with the State Street Energy Select Sector SPDR ETF, EOG Resources, Diamondback Energy and Targa Resources each gaining more than 1%. Novartis rose about 4% after saying its oral BTK inhibitor remibrutinib met the primary endpoints in the REMODEL-1 and REMODEL-2 Phase III trials for relapsing multiple sclerosis. The treatment reduced annualized relapse rates versus teriflunomide and also produced favorable MRI lesion and disability-progression results. Robinhood climbed 2.3% to $107.22 after Morgan Stanley upgraded the stock to Overweight and raised its price target to $150 from $124, citing product improvements and stronger customer economics. Duolingo gained 6% after Evercore ISI upgraded the language-learning company to Outperform from In Line. NIO fell about 4% ahead of its second-quarter results despite reporting a 14.5% year-over-year increase in August deliveries to 35,836 vehicles. Metallus declined roughly 3% after announcing CEO Michael S. Williams will retire on December 31, 2026, with President and COO Kris R. Westbrooks set to succeed him on January 1, 2027. Palo Alto Networks, Dell, Credo and MongoDB were scheduled to report results after the close.