It doesn't really matter where you want to invest the money, I would always advice against taking out loans to buy risky assets. You might have a good feeling about bitcoins and think there is going to be a bull market around the corner which you don't want to miss out on. But even with the best research and predictions there is no guarantee to make our desired returns. When it comes to investing borrowed money we face the risk to lose the money. In case our investments fails we will be still forced to repay the loan, which could ruin us financially for a long period of time. The best advice is to only invest the money we can afford to lose.