You have already told him enough mate  because you have pointed what is important for him to understand that there is no certainties here in crypto investments specially
in bitcoin that is very volatile and also the target of all FUD .
but if you wanted to extend your advises?
then better to tell him that He must be ready to keep that Bitcoin for long term instead of short term.
since he is only depositing 30 dollars meaning this is just a start up right?
or at least dry running of His plans inc rypto world.




understand and learn the graphs and he will find how it goes