I had never heard to term “sigma male” before coming across it in a review of David Fincher’s new movie “The Killer” by Max Read. According to Mr. Read, “sigma philosophies include social asceticism, dorm-room Nietzscheanism, weird resentment, boorish self-justification.”
Or, more simply, “If you don’t have any friends, and people don’t really want to talk to you? You might just be a Sigma Male.”
Wikipedia gives the term a more positive spin:
Sigma male is an internet slang term to describe masculine men. The term gained prominence within Internet culture during the late 2010s and early 2020s, and has inspired numerous memes, graffitis and videos. It is used to denote a male who is equally dominant to an alpha male, but exists outside the alpha-beta male hierarchy as a “lone wolf”. In the manosphere, it is regarded as the “rarest” kind of male.
Fincher is best known for the movies Se7en, Gone Girl, Zodiac, The Game, Fight Club, Panic Room, and The Social Network. All pretty dark. The Killer is available on Netflix.