A very nice husband and wife I know have put money into "One Coin" a "private" cryptocurrency that doesn't have a public blockchain!
The market cap for One Coin is listed as second only to Bitcoin on a crypto exchange called xcoinx...that doesn't make any trades. It is the only site that lists One Coin and looks like a fake exchange site set up only to lie about One Coin's market cap.
I have no idea how to help these people. They are focusing their lives on what looks like an elaborate Ponzi scheme. It is clearly multi-level marketing and has been flagged by several European governments.
How can I help them see the light?