Underlying Index Performance: The price of BIYF39.SA is heavily influenced by the performance of the underlying index it tracks. If the index constituents increase in value, the ETF's price generally rises and vice versa.

Supply and Demand: Basic economic principles of supply and demand affect the ETF's price. Higher demand than supply leads to price increases, while greater supply than demand results in price decreases.

Expense Ratio: The ETF's expense ratio, which covers management and operational costs, indirectly impacts the price. Higher expense ratios can lead to lower returns compared to similar ETFs with lower fees.

Net Asset Value (NAV): The NAV represents the total value of the ETF's holdings minus its liabilities, divided by the number of outstanding shares. The market price typically aligns closely with the NAV.

Market Sentiment: Overall investor sentiment and economic conditions can impact the demand for the ETF. Positive sentiment and a strong economy may boost demand, driving up the price.

Currency Exchange Rates: Fluctuations in currency exchange rates can affect the value of the ETF's underlying assets, particularly if those assets are denominated in a foreign currency.