Ponzi scheme is ok if you are in at the beginning of the scheme. That's what makes this interesting - it's basically a bet that other people will also believe this will go on.

Unless someone runs off with the money (and in any case, unless you are the first, you never know if you are at the "beginning")

Ponzi schemes aren't OK. They're a form of theft, both immoral and illegal.

Please justify the usage of the word "theft" to describe this if it is perfectly upfront about what it's doing. Surely you meant to say gambling.

by that logic the loto is immoral theft also, seems more like consenting individuals engaging in gambling.