Big players in the cryptocurrency space have set up their own private network for OTC trading, buying and selling billions every month among their little club. And instead of using Bloomberg, Symphony or anything of that caliber usually employed by traders on Wall Street, they just Skype it.

A small group of about twenty over-the-counter (OTC) traders and clients including big investors, miners, payment processors and hedge funds, has reached a monthly trading volume worth billions of dollars. Instead of using an online exchange like Coinbase or Kraken, the participants close major deals chatting on Skype and settle them by sending fiat via bank wires and cryptocurrency directly to each others' wallets.

According to a report by Reuters, after volumes increased ten fold year-over-year some of these cryptocurrency desks now often handle over $100 million a day. DCG's Genesis Global Trading on average trades $75 million to $80 million daily, Chief Executive Michael Moro said, and in December reached a monthly record of between $1.5 billion and $2 billion. Circle traded OTC up to $4 billion a month over the past year, spokeswoman Jennifer Hanley said.