Jakub Porzycki / NurPhoto / Getty Images Palantir shares sank following a report of security problems in a battlefield communications network the company is developing
Key Takeaways
An AI software darling's stock tumbled following a report of security problems, while an update from a major health insurer helped lift its stock on Friday, Oct. 3, 2025.
Palantir Technologies shares dropped after a report of potential security vulnerabilities in a battlefield communications system the company is developing.
Humana shared an update on the quality of its Medicare Advantage plans and reiterated its outlook, boosting shares of the insurer and others in the sector.
Shares of a major health insurer notched strong gains after the company offered a peek into the quality ratings of its plans. Meanwhile, reports of a government memo raising security concerns weighed on the stock of an AI software darling.
Major U.S. equities indexes finished Friday's session mixed as tech sector losses dragged on the Nasdaq, which slid 0.3%. The S&P 500 eked out a fractional 0.1% gain to a closing record, while the Dow added 0.5%. See here for more extensive reporting from Investopedia on the day's markets.
Humana (HUM) shares soared nearly 11% to log the S&P 500's top performance on Friday after the health insurer affirmed its outlook following an inadvertent release of government data on its Medicare Advantage plans. Shares of other health insurers also rose, with Centene (CNC) and Cigna (CI) adding 5.1% and 4.7%, respectively.
Shares of Zebra Technologies (ZBRA), which specializes in barcode readers and other smart data capture technology, climbed about 3% after the company said it completed its acquisition of Elo Touch Solutions. Management said the pickup of Elo, which focuses on customer-facing technologies like self-service systems, would expand Zebra's addressable market.
Palantir Technologies (PLTR) shares dropped 7.5% to lead decliners on the benchmark index after Reuters reported an internal Army memo pointed to vulnerabilities in a battlefield communications network being deployed by the big data analytics firm and its partners.
Shares of casino operators tumbled as Tropical Cyclone Matmo threatened the Asian gaming hotspot Macau. The potential storm-related disruption comes during the Golden Week holidays, which typically draw large numbers of visitors to the special administrative region. Shares of Las Vegas Sands (LVS) and Wynn Resorts (WYNN), which both have significant exposure to Macau, fell more than 7%.
Nike (NKE) stock slid 3.5% on Friday, giving back some of the gains posted earlier in the week after the footwear and apparel giant reported better-than-expected sales and profits for its fiscal first quarter. Although the strong performance suggested that Nike is making progress on its turnaround plan, the company warned of higher tariff costs and slumping sales for its "classic" footwear franchises.
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