U.S. equity markets were mixed by Thursday afternoon as losses in heavyweight tech and healthcare stocks kept pressure on major indexes during the shortened holiday week.

The Dow Jones Industrial Average dropped 462 points, or about 1.2%, weighed down by a sharp 23% slide in UnitedHealth (UNH, Financial) after the insurer posted weaker-than-expected earnings. The Nasdaq Composite hovered around a 0.2% loss, while the S&P 500 was last up 0.3%, swinging between gains and declines through the session.

Nvidia (NVDA, Financial) fell more than 3%, extending its decline from Wednesday when it shed nearly 7%. Earlier in the week, the company flagged a $5.5 billion charge tied to halted shipments of its H20 GPUs to China and other regions under tighter U.S. export controls.

Among gainers, Eli Lilly (LLY, Financial) surged over 15% after sharing favorable clinical trial results for a weight-loss pill. Taiwan Semiconductor (TSM, Financial) rose around 1% following stronger quarterly financials.

Despite Thursday's partial rebound in the S&P 500, all three indexes remain on track for weekly losses. Markets will close early for the Good Friday holiday, with the S&P 500 down more than 1% so far this week, while the Dow and Nasdaq are each off by nearly 3%.