Imagine a nugu rookie suddenly blowing up....

I mean groups have had one hit wonders in the past - is that an example of blowing up?

like Momoland and EXID and Brave Girls

but then within a couple of songs afterwards...they go back to normal nugudom? the question is always how does a group sustain that momentum

Well BTS was an almost nugu group when they debuted. Sure they got some tractions, more than many gg, but they were behind top bg. Then they took the market and Hybe bought pretty much other label. SM was vampirized by them. Now Hybe don't want their ex-employees to sign with other label (adding exclusive clauses in their contract). YG is lost without BlackPink who doesn't care that much. Rosée stopped to register her music in korea because she earns more within the US system. You can see all those ex-YG producers creating and joining other labels. Only JYP seams not affected but I don't know if they can maintain their momentum. Hybe is playing a monopoly game, and it's not good at all for music diversity. We actually get copycat of recepts.