How is the bid/ask price of an ETF determined

The trading price of an ETF should be very close to its reference NAV. However, the trading price of an ETF is influenced by market supply and demand and may differ from the reference NAV. Excessive demand may cause the ETF to trade at a price higher than the reference NAV and vice versa. When the trading price is above its reference NAV, there is a premium. Conversely, when the trading price is below its reference NAV, there is a discount.