Key Takeaways

Major U.S. equities ticked lower as the post-election rally that lifted major indexes to record highs lost momentum a week after voters headed to the polls.

The S&P 500 fell 0.3% on its first down day since the election. The Dow dropped more than 350 points, ending Tuesday's session 0.9% lower, while the Nasdaq slipped 0.1%.

Mosaic ( MOS ) shares plunged 7.7%, the S&P 500's weakest performance on Tuesday, after the fertilizer maker reported third-quarter sales and profits that came in below analysts' forecasts . Volume declines across the company's potash, phosphate, and Mosaic Fertilizantes segments dragged on performance. Mosaic also announced that its chief financial officer (CFO) will step down at the end of the year.

The CEO of GE Vernova ( GEV ), the energy equipment maker that completed its separation from General Electric in April, said the firm does not expect sales opportunities for new offshore wind energy projects until the market environment improves. The industry has been navigating supply-chain issues and interest-rate pressures. The re-election of vocal wind energy opponent Donald Trump also added to the uncertain outlook. Shares of the wind turbine manufacturer fell 7.4% on Tuesday.

Amgen ( AMGN ) shares sank 7.1% as investment bank Cantor Fitzgerald flagged possible safety issues with MariTide, the biotechnology firm's experimental anti-obesity drug. According to analysts, data from clinical trials increased concerns about bone mineral density loss among patients taking the weight-loss treatment.

Tyson Foods ( TSN ) shares posted the strongest daily gain of any S&P 500 stock, soaring 6.5% after the meat processor beat sales and profit estimates for its fiscal fourth quarter. Year-over-year increases in beef and chicken sales drove the increase. Lower costs, especially a retreat in the price of grain used to feed chickens, also contributed to the strong results.

Shares of medical device maker Dexcom ( DXCM ) popped 5.7% higher following reports that the company has officially opened its first manufacturing facility outside the U.S. The maker of continuous glucose monitoring (CGM) devices for patients with diabetes said its new plant in Penang, Malaysia, was an important investment in the country and a key part of plans to boost its global capacity.