The lesson is that in regarding money, never use when it is not your own. Though family business was not affected but still a bad impact will touch the business. And the younger one is not matured enough I think to handle the money .So everyone should not give such type of access to anyone who has no responsibility.
Yes, it is true that money that does not belong to me should never be spent. Those who are intelligent and have enough mature knowledge about it will never do such a thing. Responsibility is the biggest deposit. Those who are given responsibility and cannot fulfill that responsibility can never be good people to people. Here his brother trusted him a lot and left him bitcoin for his business transactions with him. Here he betrayed his brother, which he did a big mistake. But everyone should learn from this that everything should not be left to anyone, even if someone is given responsibility, it is still important to take account every day and see if the money is in the right place.