When a bro is so chill everybody aroun him starts to adore him in a way like no other. Also being supacash means you are the most chill bro at a party. You also have to have sicknasty flow to be considered supacash.
Guy: chugs three beers and starts to John Wall, while sporting sicknasty flow with sweet shades.
Friend: HOLY SHIT that guy is supacashh!!