And it's been a stunning thing to witness: when the Winklevoss's invested in Bitcoins, the currency was trading at just $120. Even JP Morgan's senior analyst Tom Lee has confirmed the optimistic estimates it wants to climb within five years to $ 25,000, endorsing his undisputed commercial success.
That stratospheric rise has made millionaires out of many of bitcoin's early backers, but the twins are believed to be the first public figures to have turned an investment into more than US$1 billion, the Daily Telegraph reported on Sunday.
Bitcoin suffered big price falls last week but recovered over the weekend.
Bitcoin hit a record high on Sunday closing at $11,826.76.
Still, the twins themselves have noted that older Bitcoin aficionados probably have larger holdings. While some bitcoin users were afraid that Silk Road represented a significant amount of spending in the cryptocurrencies, the twins saw opportunity.
"We've never sold a bitcoin, we're in it for the long haul", Cameron added.
Bitcoin has attracted interest from both ordinary investors and institutions.
There is also a steady increase in interest from institutional investors. Last week it emerged that the exchange operator Nasdaq could follow its rival CME Group in launching bitcoin future contracts next year, a sign that professional investors are increasingly taking the asset seriously. So yeah, looks like virtual currencies are here to stay.
The Winklevii's bitcoin wallet is among a very small handful to have reached the billion-dollar mark, according to The Telegraph, one of the others being the currency's mysterious inventor Satoshi Nakamoto.