The Daily Brief: October 23, 2026

The Justice Department filed a federal lawsuit Thursday (Oct 22) to stop Alaska from certifying its U.S. Senate race if Republican Sen. Dan S. Sullivan loses to Democrat Mary Peltola. The suit says a second candidate on the ballot, Daniel J. Sullivan, could confuse voters, and asks for a pause on certification while officials investigate. An election law expert quoted by CNN called the legal theory "strange and unusual."

With Election Day on Nov. 3, about 21 million people have voted early by mail or in person, according to the University of Florida's Election Lab, as cited by NPR. NPR reported early turnout in battleground states is well above the last midterm, but cautioned that early numbers don't predict final results.

Moderna and Merck reported that adding a custom mRNA vaccine (intismeran) to the immunotherapy drug Keytruda after surgery cut the risk of melanoma returning or death by 42% compared with Keytruda alone. The phase 3 trial included 1,137 high-risk patients. Overall survival data aren't mature yet, and the treatment still needs regulatory approval.

On Thursday the S&P 500 fell 1.2% to 7,663.43, its worst day since July. The Nasdaq dropped 2.6% to 26,008.86, its worst day since June. The Dow edged up 11.89 points to 52,867.98. Chip stocks led the decline after AI-related earnings, including Meta's, renewed worries about AI spending, and oil hit a five-month high on Middle East tensions.

On Oct 22 the Treasury Department proposed rules to carry out the COINS Act, a 2025 law. The rules would require US investors to notify the government of, or in some cases avoid, certain investments in sectors such as semiconductors, AI, quantum computing and biotechnology tied to China, Russia, Iran, North Korea and Cuba. Publicly traded stocks and many fund investments are exempt, and public comments are due Dec. 7.