Underlying Asset Performance: The primary driver is the performance of the securities held within the GRE.PA ETF. If these assets increase in value, the ETF's price typically rises, and vice versa.

Supply and Demand: Market forces of supply and demand for the GRE.PA ETF itself influence its price. Higher demand generally leads to price increases, while greater supply can cause prices to fall.

Net Asset Value (NAV): The NAV is the per-share value of the ETF's underlying assets. The market price of GRE.PA usually trades close to its NAV, but deviations can occur.

Expense Ratio: The ETF's expense ratio, which covers management and operational costs, indirectly affects its price by reducing the overall return to investors.

Market Sentiment: General market sentiment and investor confidence can impact the price of GRE.PA, especially during periods of volatility or uncertainty.

Currency Fluctuations: Since GRE.PA is priced in Euros, fluctuations in the exchange rates between Euro and other currencies can influence its attractiveness to international investors and thereby its price.