Can I short ETFs?

Short selling means you borrow shares and sell them, hoping to buy them back later at a lower price. Many brokers allow shorting ETFs if the ETF is "shortable" (shares available to borrow) and you have the right account permissions (typically margin approval).

Shorting also introduces margin requirements and the possibility of losses that can exceed your initial investment (because a price can rise without limit). FINRA's margin rules and broker policies drive a lot of the mechanics here. (finra.org)

Extra paragraph: before shorting an ETF, it's worth checking (1) borrow availability and borrow cost, (2) dividend/distribution implications (short sellers often owe payments in lieu), and (3) whether a simpler tool fits your goal, like an inverse ETF. Inverse/leveraged products have their own risks, but they avoid some of the operational complexity of shorting.