If you really care about your friend better to tell him everything, and teach them how to play in the market. Im not saying that you idea is illegal, its legal as long as you are committed but again teaching him about cryptocurrency is the best thing that you can do, let him enjoy the cryptomarket.
sharing knowledge with close friends or relatives is very good, besides being more educating so that our success is enjoyed with us, success that has no effect on the surrounding environment that I feel is just vanity, because we are not always at the top because one day we also need help from others, so let's start sharing knowledge about bitcoin and how to trade properly.