Direction of S&P 500: SPXU is designed to be inversely related to the S&P 500. A rising S&P 500 generally leads to a price decrease in SPXU.

Leverage: SPXU is a 3x leveraged ETF. This means its daily performance aims to be three times the inverse of the S&P 500's daily performance.

Time Decay: Due to the daily rebalancing required to maintain its leverage, SPXU experiences time decay, especially during periods of market volatility or sideways movement. Over longer periods, this can significantly erode its value.

Investor Sentiment: Demand for SPXU can increase when investors anticipate a market downturn, pushing its price up, and decrease when optimism prevails.

Expense Ratio: The expense ratio represents the cost of managing the ETF, deducted from its assets, impacting the returns to investors.

Trading Volume & Liquidity: Higher trading volumes and liquidity usually result in tighter bid-ask spreads and easier execution of trades, influencing the price investors pay or receive.

Management Strategy: The fund manager's effectiveness in achieving the 3x inverse daily target affects the ETF's performance and thus, its price.