>>212016481
Sigma is kind of old, it appeared within the redpill people in the beginning, and was popularised at the same time as incel.
There was an studio about wolves being alphas (leaders of the pack) or betas (followers), the studio was debunked, but people ran with it to classify humans too.
Sigma is a Greek letter, Σ, and it's supposed to be a male who doesn't follow the pack, who is outside of social norms, but in a cool way.
If you are a loser that doesn't follow the social norms then it's omega, the last letter of the Greek alphabet.