Short Bitcoin refers to an investment strategy where one predicts that the price of Bitcoin will fall. In this approach, the investor borrows Bitcoin and sells it with the hope of buying it back at a lower price in the future. If the price of Bitcoin does go down, the investor can buy back the Bitcoin at a lower price, return it to the borrower, and profit from the price difference. However, this strategy is also high-risk, because if the price of Bitcoin goes up, the investor could suffer a huge loss.