There's probably enough collateral involved that they come out ok either way. In other words you'd secure the loan against some bitcoin you already have that's

There's probably enough collateral involved that they come out ok either way. In other words you'd secure the loan against some bitcoin you already have that's maybe worth 2x what you're borrowing. So now you're holding 3x that amount. Ideally bitcoin goes up, you sell, then repay the loan and take profits. If btc drops too much, you need to dump your coins and repay the loan. My guess anyway.