Underlying Asset Performance: The primary driver is the performance of the companies held within the BIYE39.SA ETF. If the constituent stocks increase in value, the ETF's price generally rises, and vice versa.

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

Investor Sentiment: Overall market sentiment and investor confidence in the sectors or themes represented by the BIYE39.SA ETF can impact demand, subsequently affecting its price.

Economic Conditions: Macroeconomic factors such as interest rates, inflation, and GDP growth can indirectly influence the valuations of the underlying companies and, consequently, the ETF's price.

Currency Fluctuations: Changes in the relative value of the local currency against other currencies can affect returns for international investors, influencing demand and the ETF's price.

Dividend Payments: Dividend distributions from the underlying companies impact the ETF's Net Asset Value (NAV). While dividends are ultimately paid to ETF holders, their announcement and ex-date can influence short-term price movements.

Expense Ratio: The ETF's expense ratio, which represents the annual cost of managing the fund, indirectly affects its total return and attractiveness to investors, which can influence its price.

Liquidity of Underlying Assets: The ease with which the underlying stocks can be bought and sold can impact the ETF's ability to track its index efficiently, potentially affecting its price.