My Big Coin is the cryptocurrency regulators warned you about. The Commodities Futures Trading Commission (CFTC) has filed charges against My Big Coin (MBC) and its founders for misappropriating more than $6 million from customers in a cryptocurrency-fueled Ponzi scheme. While the company gave the illusion it had inked a deal with Mastercard, not to mention promoting a gold-backed coin for its digital wallet, investors eventually grew suspicious only to have those concerns squashed by the company under the guise of more coins.