Probably a progesive KO ( knouckout ) tournament
It means that 9$ are the main prizepool
Also you get 9$ when you bust a player ( 4,5$ in your account and 4,5$ on your bounty )
And the 2$ represent the rake.
It is probably virtual money because i looked and there is $ mark everywhere for real money...i just wrote knock out and it opened all the tournaments...for virtual and real money