The Commodity Futures Trading Commission said it is suing Cash FX Group and three individuals in a $950 million foreign-exchange investment case involving cryptocurrency.

The defendants are Cash FX and its CEO Huascar Jose Lopez Castillo of Brazil, The Conversion Pros and its CEO Ronald Pope of Oregon, and Justin Halladay of Florida.

The CFTC said its complaint was filed Friday in the US District Court for the Middle District of Florida. It alleges the defendants operated a multilevel marketing Ponzi scheme, soliciting and accepting over $950 million for the purported purpose of trading retail foreign currency contracts in a commodity pool.

The agency alleged the defendants falsely claimed pool funds were handled by expert traders,…