The ProShares UltraPro S&P 500 (UPRO) closed down 3.5% at $89.66 on December 30, 2024, as U.S. equities faced a broad sell-off amid year-end profit-taking and concerns over rising Treasury yields. The S&P 500 fell 1.07%, with major indexes extending losses from Friday, driven by light trading volumes and a lack of significant news catalysts. Investors appeared to be locking in gains after a year marked by more than 50 record highs, leading to a "Santa stumble" instead of the anticipated rally. The 10-year Treasury yield, which influences market expectations for interest rates, retreated to 4.55% from 4.63% on Friday, yet remained a focal point for market volatility. Large-cap tech stocks, including Apple and Microsoft, were among the hardest hit, contributing to the broader market decline. Boeing shares also fell sharply following a fatal crash involving one of its aircraft, adding to the negative sentiment.