There are crypto exchanges that allow naked shorting. As long as you hold the equivalent USD or EUR amount in the exchange, Cexio for example will let you margi

There are crypto exchanges that allow naked shorting. As long as you hold the equivalent USD or EUR amount in the exchange, Cexio for example will let you margin short BTC with 3x leverage, when you don't actually own the BTC. I'm not saying you should, just that you can.