How do ETFs trade?

ETFs trade on stock exchanges, so you buy and sell them through a broker using a ticker symbol. The price you see is a market price determined by supply and demand, and it updates throughout the day. (finra.org)

A key feature is the arbitrage mechanism: authorized participants can create or redeem large blocks of ETF shares using the underlying securities. That process helps keep the ETF's market price close to the value of its holdings (NAV), though small premiums/discounts can happen. (sec.gov)

For everyday investors, the most practical implication is execution: watch the bid/ask spread, consider limit orders if spreads are wide, and remember that liquidity also depends on how liquid the underlying holdings are.