Good for you and your friend, you made the right decision. Let your friend decide for himself because it's his money, so it's better for him to know what to do with his money. And you will not bear any responsibility if his investment unfortunately loses. Try to give him all the knowledge about bitcoin.
Giving him knowledge about Bitcoin is also the same as directing him to a better place even though the final decision is in the hands of his friend. And since no one is held accountable when a friend loses on an investment, this is where every piece of good advice is needed before making a hasty decision. Because a wise enough decision will provide a few steps that might be better for people who are trying to invest in their life.
Just answer if ever they would really be having some questions or something that they would really be liking to know.As a friend, then this is where you should really be minding on and be sure of that you shouldnt really make out some assurances because this is where people do make out some mistakes and make up some argumentation or quarrels on the time that the market would be fuck*ing up your investment on which you would be the ones who would really be getting blamed and this is something that we dont really like to happen. This is why we should really be that careful when it comes to this manner.
Give them and make them know about the pros and con's of this market and dont solely focus on the positive.