Underlying Asset Performance: The primary driver is the performance of the securities held within the ETF. If the underlying index or basket of stocks increases in value, the ETF's price should generally rise, and vice versa.

Supply and Demand: Market forces of supply and demand for the ETF itself influence its price. Higher demand tends to push the price up, while increased selling pressure can lower it.

Interest Rates: Changes in interest rates can impact the valuations of companies and their stocks, indirectly affecting the ETF's price. Higher rates can lead to lower valuations, and lower rates to higher.

Economic Conditions: Overall economic health, including factors like GDP growth, inflation, and unemployment, affects company earnings and investor sentiment, subsequently impacting the ETF's worth.

Currency Fluctuations: For ETFs holding foreign assets, currency exchange rate movements can affect the ETF's price when translated back to the local currency.

Fund Management Fees: The fees charged by the fund manager can indirectly affect returns and, therefore, the long-term price performance of the ETF, albeit usually marginally.

Investor Sentiment: General investor confidence and attitudes towards the market sectors the ETF tracks can influence buying and selling activity, driving price fluctuations.

News and Events: Major news events, policy changes, or industry-specific developments can significantly impact the value of the underlying assets and, thus, the ETF's price.

Liquidity of Underlying Assets: How easily the ETF's underlying holdings can be bought or sold affects the ETF's overall liquidity and pricing. Less liquid assets can lead to wider bid-ask spreads.

Arbitrage Activity: Market makers and arbitrageurs help keep the ETF's price aligned with its net asset value (NAV) by exploiting price discrepancies, which can influence price movements.