UPDATE: Cameron and Tyler Winklevoss, according to several published reports, became the first bitcoin billionaires over the weekend as the cryptocurrency surged to an all-time high of $11,773 on Sunday, a recovery from last week's 20 percent drop. Bitcoin prices weren't quite at records on Monday. But at a market value of nearly $191 billion, bitcoin was about halfway to the "small bull case scenario" described by the Winklevosses in 2013. Here's a story on the interview they did four years ago:

The Winklevoss twins are screaming bulls on bitcoin. Cameron and Tyler Winklevoss — big investors in the digital currency — said Tuesday that bitcoin should be worth at least 100 times more than it's valued today. "The small bull case scenario is a $400 billion market cap. So the market cap is around $4 billion right now," Tyler Winklevoss said in an interview at the DealBook conference that aired on CNBC's "Squawk Box." The twins, who famously battled Mark Zuckerberg over the origins of Facebook, started buying bitcoin at $9. Their investment was worth $11 million in April at $120 per coin. After a sharp drop, bitcoin has surged into record territory again, hitting $385 in early Tuesday trading on Mt. Gox — one of the many exchanges for the digital currency. Cameron Winklevoss said he views their investment in bitcoin as a gold 2.0 play but also a bet on the technology: "The idea that payments are increasingly going to use a network like the bitcoin network to move money around the world."

Cameron (L) and Tyler (R) Winklevoss. Adam Jeffery | CNBC