Okay kiddo, so you know how sometimes people buy things and then sell them later to make more money? Well, grown-ups do that with something called stocks.
r/wallstreetbets is a website where people talk about buying and selling stocks. But it's not just any stocks - they like to talk about stocks that might make them a lot of money quickly, but also might lose them a lot of money quickly.
It's like playing a game where you can win big, but you might also lose all your "money". They call it "YOLO" - which means "you only live once" and it's like saying "let's take a risk and see if we can make a lot of money fast".
Some people on r/wallstreetbets are really good at picking stocks that make them a lot of money, while others aren't so good and might lose a lot of money. It's important to remember that it's just a game, and not real life - so it's not something you should do with your own money until you're all grown up and really understand how it works.