One of the biggest rules of investing in traditional investments is to NOT to use money that isn't yours, on BitMex this would be known as Margin trading. I wouldn't even want to do this with a less volatile and less risky investment, which would be stocks and bond funds / regular stocks. I would NEVER want to do this in Crypto where it's insanely volatile, risky, and that the margin trading fees are pretty high. Investing here is risky enough.