Can I buy ETFs on the weekend?

For most ETFs, trading happens during the exchange's trading hours. On weekends, those exchanges are typically closed, so you generally won't get a trade executed until the next market session.

Some brokers let you place an order on Saturday or Sunday (queued for later), but execution will depend on the market being open and your order conditions (market vs limit, time-in-force, etc.).

Extra paragraph worth knowing: even if you could access some kind of weekend pricing (certain brokers offer limited "overnight" style trading for some assets), it's not the norm for ETFs, liquidity is usually thinner, and spreads can be worse. If you're placing an order outside normal hours, a limit order is often the safer default.