The term "Yyybbb" is mentioned in the context of a TikTok video [1] and also appears to be the username of an individual or entity in the same video [3]. However, there is no direct information provided in the contexts about why Yyybbb is trending. It is important to note that there is a potential association of the name "Yyybbb" with a reportedly fraudulent website [6], but there is no confirmation or explanation given regarding any connection between the TikTok video and this potential fraudulent activity. Therefore, I cannot provide a definitive answer as to why Yyybbb is currently trending.