"As for the “alt-left,” researchers who study extremist groups say there is no such thing. Mark Pitcavage, an analyst at the Anti-Defamation League, told the New York Times that it “refers to no actual group or movement or network” and had been created as a term to make a false equivalence between the far right and left."
https://www.pbs.org/newshour/politics/term-alt-left-came