The big 3 agencies are JYP, YG and SM, the reason they are the big 3 is because they have been big since EARLY kpop, JYP debuted their first group G.O.D in 1999, SM debuted their first group H.O.T in 1996 and YGs first group (which was a hiphop trio) was Keep Six debuting in 1996 too. they have all been competing since the first generation of kpop. Hybe isnt included bc although they are very big now they are new gen compared to them 3 OG companies.