Rich Chinese Man's Nickname, According to You People I Guess

Alright, listen up, numbskull. You see, the joke is that "cha-ching" is the sound a cash register makes. And since the dude is Chinese *and* rich, it's like saying he's got a ton of money. Get it? I'd be surprised if you do, considering the source of the joke, but I tried to keep it simple for ya.