Underlying Index Performance: The ETF's price closely tracks the performance of the index it replicates. If the index constituents rise in value, the ETF's price typically increases and vice-versa.

Supply and Demand: Market forces of supply and demand for the ETF itself directly influence its price. Higher demand can lead to a premium over Net Asset Value (NAV).

NAV: The Net Asset Value, calculated daily, is a key determinant. It reflects the collective market value of the ETF's underlying holdings.

Expense Ratio: While not a direct price driver, the expense ratio impacts long-term returns. Higher ratios reduce the overall investment gains compared to lower cost ETFs.

Tracking Error: The divergence between the ETF's return and its benchmark index's return is known as the tracking error. Higher error can make it less attractive to investors.

Market Sentiment: Broad market sentiment, risk appetite, and economic outlook influence investor decisions, indirectly impacting ETF demand and thus price.