My question is did he trade or did he just buy at a right time then sold at a right time? I think you should inform him that bitcoin is doing really well right now because it is currently on a bull run but there are possibilities that bitcoin will not be doing so well later on. Sure, it can recover but there would be hard times. Regardless whether how good bitcoin has been treating him, I do not think we should only depend on one source of income. We should always have safety nets.