Wall Street ended lower on Wednesday as rising Treasury yields pressured megacap stocks, with Nvidia, Apple, and Meta among the biggest losers. The 10-year U.S. Treasury yield hit a three-month high, leading investors to reassess the potential for future Fed rate cuts. McDonald's fell due to an E. coli outbreak linked to its burgers, while Coca-Cola declined despite reaffirming its profit growth forecast. Analysts believe market volatility could increase as the Fed and upcoming election test market resilience.