I'm sorry if my questions seems vague but it's very hard to explain. I came across many Vietnamese who told me they lost a lot of money by being betrayed by "friends" in some type of pool. My Vietnamese-Canadian friend tried to explain to me. It's something like you're in a pool of money with people, each of them have to pay some interest every now and then, but it has "good potential" and the money can grow over time... but my friend told me all it takes is one person to leave with all the cash and you lose all. Since gambling is very taboo in Vietnamese culture, and even though this is not strictly speaking gambling I have the feeling many people do this here but they won't talk about it.
Anyone knows what I'm talking about and could clearly shed the light of what scheme this is? My girlfriend currently has some money in this and I would like to understand fully before I scold her