For $400, I don't think that would put your life in danger unless you are living in a country where poverty poverty rate is high and that amount is so huge.
That amount in my country can be earn through their salary so even if you brag that amount, you'll not get harm.
Maybe around $10,000 or more, that would already put your life in danger.
But still, for some people who live in the poverty rate is high will be dangerous as you say. $400 is not too small or not too big to tell to other people but it still better to keep it for ourselves so no one will know about that. If we want, we can share that win money to other people who needed, and maybe we can also celebrate with family and friends too.
Whatever you earn is yours and as far as money is concerned, nobody becomes happy for you in game because everyone is competing against you. You better share gambling tips instead of the money amount that you won. Sharing it with your family is going to make them happy as they have are the ones who are always standing by you in hard times. Moreover I would personally like sharing it with poor ones as well because it gives satisfaction.