Underlying Index Performance: The ETF's price closely tracks the performance of the underlying index it aims to replicate. Upward movement in the index's constituent stocks will generally lead to an increase in the ETF's price.

Supply and Demand: Higher demand for the ETF relative to its supply will drive its price up. Conversely, increased selling pressure or lower demand can cause the price to decline.

Market Sentiment: Overall market conditions and investor confidence can influence ETF prices. Positive sentiment often leads to increased investment and higher prices, while negative sentiment can trigger selling pressure and lower prices.

Expense Ratio: While not directly affecting daily price swings, a higher expense ratio can slightly reduce the long-term returns of the ETF compared to similar, lower-cost options.

Dividend Payments: Dividend distributions from the underlying stocks held by the ETF are passed on to ETF holders. The ETF's price may slightly decrease around the ex-dividend date as the dividend is factored out.

Currency Fluctuations: If the ETF holds assets denominated in foreign currencies, fluctuations in exchange rates can impact its price when translated back into the local currency.

Tracking Error: The degree to which the ETF's performance deviates from its underlying index. Greater tracking error can lead to a price that doesn't perfectly reflect the index's performance.