がっちゃう
agacchau

Godan Verb (ru)
Godan Verb (u)

The completive aspect (contracted form) - indicates completion or regret of 揚がる

1. To rise/go up/become known (and now it's too late/regrettable); To be raised/promoted (and now it's too late/regrettable)

Completed Action
Colloquial