The ProShares Ultra S&P500 ETF (SSO) closed at $96.98 on January 29, down 0.9% as the broader market reacted to the Federal Reserve's decision to leave interest rates unchanged. The S&P 500, which the ETF tracks, fell 0.47% to 6,039.31, influenced by a mix of factors including the Fed's cautious stance on inflation and the ongoing impact of the DeepSeek AI developments. Nvidia, a significant component of the index, saw its shares drop 4% amid concerns over potential U.S. restrictions on chip sales to China, further weighing on the tech-heavy index. The Fed's decision to maintain the federal funds rate between 4.25% and 4.50% was accompanied by a statement highlighting persistent inflation and a stable labor market, which contributed to market uncertainty. Investors are also bracing for a series of earnings reports from major tech companies, adding to the cautious sentiment.