You can invest in any percentage of your money, but you need to accept the risk of investing in cryptocurrency. The cryptocurrency has volatility, and that makes the price of all coins will always up and down, and that makes people can panic to see the price moves. But if you can control yourself when you know the market, and you want to use bitcoin as your long term investment, then you don't have to worry or panic because bitcoin won't let you down, and bitcoin will give you the profit.

Before you investing some of your money, you need to learn the basics information about cryptocurrency, learn about why you don't have to panic in investing in bitcoin, and you can solve the problem that might comes after you invested. Using 40% of your money will be useful, but you don't have to use all of the money you have if you still need the money for your daily life.