Underlying Asset Performance: The primary driver is the performance of the assets held within the ETF. Stocks, bonds, or other investments rising or falling directly impact the ETF's net asset value (NAV).

Supply and Demand: Market forces influence the trading price. High demand relative to supply can push the price above the NAV, while excess supply can lead to trading below NAV.

Market Sentiment: Overall investor optimism or pessimism affects demand for ETFs, impacting its price. Broad market trends also have considerable effects.

Interest Rates: Changes in interest rates can impact fixed income assets, thereby affecting bond ETFs or ETFs with significant bond holdings. Higher rates generally decrease bond values.

Currency Fluctuations: If the ETF holds assets denominated in foreign currencies, exchange rate fluctuations can influence the ETF's value when translated back to the base currency.

Expense Ratio & Management Fees: While not directly impacting daily price fluctuations, higher fees can slightly reduce long-term returns and competitiveness, indirectly affecting demand and price.

Issuer Reputation & Size: A well-regarded issuer with a large and liquid ETF generally inspires more confidence, potentially leading to more stable and predictable price movements.

Index Tracking Accuracy: How closely the ETF tracks its benchmark index impacts its value. Deviations from the index due to tracking error can affect returns and investor perception.

Economic Indicators: Macroeconomic data releases such as GDP growth, inflation rates, and employment figures influence market sentiment and affect the underlying assets, thus impacting the ETF's price.