The fourth band in thrash metal’s “Big Four” is Anthrax. The commonly accepted quartet consists of Metallica, Slayer, Megadeth, and Anthrax—four American bands credited with popularizing thrash metal during the 1980s.
Anthrax formed in New York City in 1981 and became known for combining rapid, heavily distorted guitar work with energetic performances and, later, elements of hardcore punk and alternative metal. Albums such as Among the Living (1987) helped establish the group as a major force in the genre. The band also gained attention for collaborating with Public Enemy on “Bring the Noise.”
Exodus and Testament were highly influential Bay Area thrash bands, while Overkill was a major New Jersey act, so their inclusion can seem plausible. Some writers informally discuss a larger “Big Five” that includes Exodus, but “The Big Four” has a standard canonical membership: Metallica, Slayer, Megadeth, and Anthrax.