About 7.12 million Bitcoin, or 35.4% of every coin in existence, now has a weak spot. Most owners can fix it in minutes. Satoshi Nakamoto’s coins may never be fixed.
Analytics firm Glassnode counted coins whose “public key” already shows on Bitcoin’s public ledger. Think of a public key as a lock anyone can study. Today’s computers cannot pick it. A large enough quantum computer, in theory, could, and then move the coins.
Whose Bitcoin is Exposed?
Glassnode says 25.8% of supply is exposed because people reused addresses.
Exchanges hold 11.6% of supply in exposed addresses. Glassnode’s entity data puts Robinhood at 100%, Binance at 85% and Coinbase at about 5%. US government holdings show none. Glassnode says these are not security ratings.
Coinbase holds Bitcoin for most US spot ETFs. One of its analysts has warned of quantum threats, and on October 29 its CEO said work is underway.
“We have begun the work to upgrade our custody to be post-quantum.”
Why Satoshi’s Coins Can’t Be Fixed
For reused addresses, one transaction ends the risk.
“Moving those coins to a fresh address ends this exposure,” Glassnode noted.
About 1 million BTC sits in early addresses linked to Satoshi, according to Ethereum Foundation researcher Justin Drake. They have not moved in over 15 years.
A draft proposal from Casa’s Jameson Lopp would freeze coins that never upgrade, Satoshi’s included. Blockstream CEO Adam Back prefers optional upgrades.
Should Investors Worry Yet?
In March, Google said a quantum machine with under 500,000 qubits could break this kind of encryption in minutes. No such machine exists. Back has said one may be 20 to 40 years away.
At Bitcoin’s current market price, the exposed coins are worth more than $500 billion. An earlier ARK Invest estimate flagged over $480 billion. CoinShares counted only about 10,200 BTC worth targeting for real market impact.
Nasdaq-listed Next Technology Holding approved selling or pledging about 5,833 BTC on October 30, citing quantum computing among other risks.
Lopp’s plan and BIP-360, a separate draft, have no activation date. The quantum threat timeline remains Bitcoin’s open question.
