XUS.TO is an ETF that tracks the S&P 500 index. S&P 500 Performance: The primary driver is the performance of the S&P 500 index itself. When the index goes up, the ETF's price tends to increase, and vice versa.

Currency Fluctuations: As the S&P 500 is USD-denominated, exchange rate movements between the Canadian dollar (CAD) and USD impact the CAD price of XUS.TO. A stronger USD makes the ETF more expensive for Canadian investors.

Supply and Demand: General market sentiment and investor demand for XUS.TO can affect its price. High demand can push the price slightly above its net asset value (NAV), while low demand can cause it to trade at a discount.

Management Fees: The ETF's expense ratio slightly reduces the returns for investors over time, relative to the index. This is a minor, ongoing factor.

Dividend Reinvestment: Dividends paid by the companies within the S&P 500 are reinvested, contributing slightly to the ETF's overall return and price.

Trading Activity: High trading volume and volatility in the market can lead to short-term price fluctuations in XUS.TO.

Economic Data: Macroeconomic indicators like inflation, interest rates, and GDP growth in the US can influence the S&P 500 and, consequently, the price of XUS.TO.