Underlying Index Performance: BX4.PA's price mirrors the inverse performance, multiplied by four, of its underlying index. Declines in the index typically lead to price increases in BX4.PA and vice-versa.

Leverage Factor: The 4x leverage magnifies both positive and negative movements of the index, resulting in higher volatility and price swings for BX4.PA compared to a non-leveraged ETF.

Interest Rates: Interest rates impact the cost of maintaining the leveraged position. Higher rates can increase costs, potentially dampening BX4.PA's performance.

Market Sentiment: Overall market optimism or pessimism can strongly influence demand for leveraged inverse products like BX4.PA, driving its price irrespective of short-term index movements.

Trading Volume & Liquidity: Low trading volume and limited liquidity can lead to wider bid-ask spreads and price slippage, affecting the execution price for buyers and sellers of BX4.PA.

Management Fees & Expenses: The ETF's operating costs, including management fees and other expenses, are deducted from its returns, impacting its overall price performance over time.