U.S. equities saw sharp sector divergence in Tuesday's session, driven by major regulatory news and corporate earnings. Health insurers led the decliners, while several industrial and technology names posted significant gains.

Health Care Sector Under Pressure
Shares of major health insurers tumbled after the Centers for Medicare & Medicaid Services (CMS) proposed a minimal 0.09% increase in 2027 Medicare Advantage payment rates. The figure was drastically below industry expectations of a 4-6% rise. UnitedHealth Group and Humana each plummeted 15%, while CVS Health slid nearly 13%.

Industrial and Auto Earnings Boost
Strong quarterly results and guidance propelled several manufacturers higher. General Motors jumped more than 4% after reporting better-than-expected fourth-quarter earnings, issuing an upbeat 2026 outlook, and announcing a 20% dividend hike alongside a $6 billion stock buyback program. Boeing gained 2% on revenue that topped estimates, with CEO Kelly Ortberg striking an optimistic tone.

Logistics and Tech Announcements Drive Moves
United Parcel Service (UPS) rose 3.6% after delivering quarterly results that exceeded analyst forecasts on both revenue and profit. In technology, Corning rallied 5.9% following an exclusive CNBC interview where its CEO revealed a commitment from Meta Platforms for up to $6 billion in fiber-optic cable orders through 2030 for AI data centers. Salesforce added 2.4% after securing a $5.6 billion, 10-year contract with the U.S. Army.

Mixed Results for Airlines and Others
American Airlines climbed nearly 3% despite a fourth-quarter earnings miss, as investors focused on the carrier's bullish 2026 revenue projection of 7-10% growth for the first quarter. Conversely, Nucor fell more than 2% after its steel earnings report missed expectations, and Sanmina slid over 9% following its latest financial release.

Activist Campaign Emerges
Shares of CoStar popped nearly 6% after hedge fund Third Point launched an activist campaign targeting the real estate analytics firm.