Avoid ending up like a friend, who used all the money he has to invest in bitcoin and also took a loan, promising the lender that he will pay back when he gets paid in a month, after a month he never received the salary, I warned him doing this, because he has no doubt mixed investment with 'whatever it takes', is it safe to call this greed? I don't know.
Now he wants me to lend him some money to at least pay the loaner back and later settle me, there is more, now I have to send him some money to buy some food.
You don't have to use all your money to invest, even if you are not married yet or have other responsibilities, the best approach when planning to invest in Bitcoin is to buy with some percentage of the money you earning, maybe through business or a job.
If you do this weekly or monthly you won't feel any pressure, always remember that health is wealth.
The thing is I think he invested in a scam, I mean in an MLM where they promise him that in small span of time his money maybe in bitcoin type will increase maybe about 2x or 3x, some other people who are new to crypto still believes in this thing, I wonder why he didn't ask you before. And I think the only way 6ou may able to help him is teach him that not all projects, ads or investments using the word bitcoin is true and he will get things so quick. It is kinda hard to be in that situation but eventually he will pass through it.
We don't need to know if OP's friend invested in bitcoin or a scam MLM project, but we shouldn't invest with all our savings either. Even if it is bitcoin, it is no guarantee that his money will not be lost, bitcoin is also risky. OP's reminder is very true no matter where we invest but never invest all your money, it is wrong and not recommended.