MarketCatalystU.S. stocks fell at midday Thursday as AI-spending worries hit chipmakers and Meta, with Moderna, TTM Technologies and Carpenter Technology plunging, while Spotify, Kohl's and Biohaven jumped and defensive and housing stocks rallied.
Shares of TTM Technologies plunged about 29% on Thursday even after record third-quarter sales, an earnings beat and a raised 2026 outlook, as investors focused on a slightly light fourth-quarter revenue guide and a delayed customer program.
Merck reported that Moderna's personalized cancer vaccine, intismeran, combined with Keytruda significantly reduced the risk of melanoma recurrence or death by 42% versus Keytruda alone in the Phase 3 INTerpath-001 trial.
Moderna shares plunged about 25% after detailed Phase 3 results for its personalized melanoma vaccine with Merck reportedly leaked online ahead of the Oct. 24 ESMO presentation.
Shares of nVent Electric fell 10.48% to $130.82 as profit-taking and valuation worries hit AI data center power and cooling infrastructure stocks, with Vertiv down 5.80% ahead of its own earnings.
Cybersecurity stocks rallied as the NSA and FBI warned of critical internet vulnerabilities, reinforcing expectations that growing AI capabilities will drive long-term demand for cybersecurity.