He was already a stock trader so I think it was easy for him to understand how Bitcoin investment works. In fact, Bitcoin investment has no big difference when it is compared to the stock market, and the returns are still almost the same.

To have a positive view when telling someone could be the best way to encourage people. We don't need to say we can be rich in here, can make your money x100 coz they could just think that this was a scam. telling the truth is great and tells him the risks and possible losses if got the wrong decision.