This is a common question about where and how to short crypto in the United States. Bitfinex and Kraken are two of the most common venues for shorting cryptocurrency in the United States. You may borrow cryptocurrency from other players and then sell it in the market using these platforms. Once you're willing to buy your short position back, all you have to do is settle the debt along with whatever interest or fee it has accrued. It is performed automatically as you push buttons, so there's no need to return anything manually.