Thrash metal is not just all about Metallica, Megadeth, Slayer and Anthrax, all of whom people in the music business (including journalists) often refer to as "The Big 4". Whenever someone talks about "The Big 4", one person would ask why bands like Exodus, Testament or Overkill were not part of it. They say it was because of record sales, or because of the fact that those mentioned bands did not blow up the way "The Big 4" did.

In particular, thrash metal fans argue that "The Big 4" should be expanded to "The Big 5", "Big 6", whatever number, or should have easily included either Exodus, Testament or Overkill instead of Anthrax or even Metallica; like "The Big 4", those three bands not only had some success, publicity and airplay on MTV's Headbangers Ball during the 80's/90's, but were part of the thrash metal movement that decade. Out of any non-"Big 4" thrash metal band, Overkill has sold over 16 million records worldwide (according to their Wikipedia page), surpassing Testament and Exodus, who have sold 1.4. million and 5 million records respectively.

In response to the fans who argue, agree, whatever, over who is and is not the "big" band, I created a petition on the idea of changing "The Big 4" to "The Big 5". The purpose of this petition is to not only show the world (including those who are new to metal) that Metallica, Megadeth, Slayer and Anthrax were not the only bands that did anything for thrash metal, but that there are plenty of good thrash metal bands who emerged from the same scene as those four bands and seem to have enough potential to be included in "The Big 5", especially Overkill, Testament, Exodus, Metal Church, Death Angel, Dark Angel, Nuclear Assault, just to name a few.