Bitcoin hit $11,395 last week, capping a boom that started a year ago and accelerated dramatically in recent days, despite a chorus of warnings about its threat to financial stability and potential for criminal exploitation.
The identical twins, who competed as rowers in the 2008 Beijing Olympics, have said recently they haven't sold any bitcoins since their initial purchase.
The twins together had $11 million U.S.in bitcoin at $120 a coin in April 2013.
Bitcoin, the original digital currency of the world wide web, has spawned its first billionaires, the Winklevoss twins. Concern over its extreme volatility has not slowed its rapid rise.
What the Winklevii is are two people now holding just over $1 billion worth of bitcoin, and that's fantastic.
"If Bitcoin is a better gold or seen as a type of gold-like asset, then it could be in the trillions on a market cap", Tyler Winklevoss told CNNMoney in 2015.
However, it seems Bitcoin's huge popularity is slowly gaining traction among private entities and financial regulators.
The Harvard University-educated rowing brothers sued the Facebook founder in 2004, claiming he stole their idea for the social networking site.
That investment money came from the $65 million the brothers' won in a lawsuit against Facebook in 2011.
Bitcoin has turned many early investors into millionaires but the Winklevoss twins are among the few current investors with a 10-figure amount.