Hacking is out of the question, it's just that Coinmarketcap has a good sense of humor, + Wallstreetbets is a subreddit where people discuss trading. Adding WSB to the top is a kind of subtle mockery of market volatility (with this gesture, SMS emphasized the fact that if ordinary traders unite, they can easily repulse financial institutions). People with WSB don't learn trading techniques, the community just sees trading as a thrill. BTW, GameStop was also discussed on this subreddit and Elon Musk did not miss the opportunity to Tweet about it.