Mircea Popescu: The Bitcoin Billionaire Who Drowned

At about 8:30 on the morning of 23 June 2021, a 41-year-old man went into the sea to swim at the Tramonto stretch of Playa Hermosa, a surf beach in Garabito on Costa Rica's Pacific coast. A current carried him out. The Red Cross took the call, paramedics found him without vital signs, and attempts to revive him failed. Lifeguards from nearby Jacó pointed out afterwards that Playa Hermosa is not a swimming beach.

Costa Rica's judicial police, the OIJ, identified him as Mircea Popescu and listed him as Polish. He was Romanian, born in Cluj-Napoca, and he was one of the best-known and most disliked figures in early bitcoin. Within days, outlets from Business Insider to Costa Rica's Teletica were asking the same question: what happens to a bitcoin fortune when the only person with the password drowns?

How big the fortune was

Nobody knows, and that is the point. Popescu claimed to hold a million bitcoin, which would have made him the largest individual holder after the network's anonymous creator, Satoshi Nakamoto. Acquaintances told reporters his accounts held about a million coins in 2016. Others believed he exaggerated and put the figure at no more than 300,000, and some estimates ran to only tens of thousands. Bitcoin was trading at a little over $30,000 on the day he died, so even the low estimates meant hundreds of millions of dollars, and the headline figure most outlets used, "over $2 billion", sat at the cautious end of the range.

No wallet has ever been publicly tied to him in a way that would settle it. A bitcoin holding is controlled by a private key, a long secret number that works like the only copy of a safe combination. Whoever has the key can move the coins; nobody else can, and there is no bank, broker or court that can issue a new one. If Popescu kept his keys to himself, his coins are still sitting where they were, visible to anyone who knows which addresses to watch, and unmovable forever.

The exchange, the blog and the feuds

Popescu came to bitcoin in 2012, after running Polimedia, a Romanian business software company he founded in 2007. In April 2012 he launched MPEx, a stock exchange priced entirely in bitcoin, where small online businesses could sell shares to bitcoin holders. Registration cost 30 bitcoin. MPEx made international news when it listed shares in SatoshiDice, a bitcoin betting site, which was sold in July 2013 for more than 125,000 bitcoin.

That brought the US regulator to his door. In February 2014 an enforcement lawyer at the Securities and Exchange Commission asked him to voluntarily hand over a list of SatoshiDice's investors and the account history of its founder, Erik Voorhees. Popescu told Bloomberg that MPEx had broken no laws, refused a phone call, and asked the SEC to show what authority it had over an exchange run from Romania. He later wrote that bitcoin should be treated as a sovereign in its own right.

His blog, Trilema, was where he did most of his talking. Bitcoin Magazine estimated that perhaps 10,000 people read it, and that its ideas, that bitcoin should almost never change, that rival coins would fail, that holders answer to nobody, helped shape Saifedean Ammous's book The Bitcoin Standard. The same magazine recorded his sexism, bigotry and anti-semitism, and said he verbally abused and encouraged violence against bitcoin's volunteer software developers. During the long fight over whether to make bitcoin's blocks bigger, he declared that his business would not accept any change to the rules. Romanian outlets also recalled a video, around 2019, of him walking two women on leashes through the centre of Timișoara.

He made some correct calls. He publicly branded Bitcoin Savings and Trust a scam in 2012; its operator, Trendon Shavers, was later charged by the SEC and US prosecutors and pleaded guilty to securities fraud. He also called Ripple a scam.

Who confirmed it, and what is still open

The death was confirmed within days by people in bitcoin who knew him, including Tuur Demeester, a partner at the investment firm Adamant Capital, and the developer Diana Coman. According to Teletica, an American woman who said she was his companion identified the body and collected it from the judicial morgue on 24 June. On 7 July 2021 the OIJ told Teletica the case was still open: it was being treated as an accidental drowning while investigators waited for the autopsy, which could either confirm that view or start a new line of inquiry. No result was published, and no later report found any sign of foul play. A handful of online sceptics suggested he had faked his death. There has never been evidence for that.

What happened to the coins is also unrecorded. No will, heir or executor has been publicly named, no court case over the estate has been reported, and as of October 2026 no outlet has reported his coins moving. A market maker quoted by ForkLog in 2021 called him one of bitcoin's "sleeping giants", holders big enough to crash the price by selling, who mostly never did.

If the coins are lost, they join an unknown pile of bitcoin that can never be spent, from early miners' forgotten hard drives to the keys that died with Gerald Cotten of QuadrigaCX. Because bitcoin's supply is capped at 21 million coins, every coin that is lost makes the rest slightly scarcer. That is the dry arithmetic of the case. The human version is shorter: a man who spent a decade telling everyone else to take sole responsibility for their own keys appears to have taken his with him.