The song "Sigma Boy" by Betsy and Maria, often associated with "Squid Game Brainrot," is a viral meme song with origins in Russian child stars' music. It became popular through TikTok, with users creating videos featuring the song and various internet trends like the "Sigma" male archetype. The song's meaning has evolved through interpretations, initially about a boy trying to win over the singers, then shifting to the idea of a "Sigma" male who is independent yet attracts everyone.