Just over 10,000 Bitcoins – out of nearly 20 million in circulation – are in wallets actually exposed to a quantum attack.
This figure comes from CoinShares, a crypto asset management company, which discovered in February that only 10,230 coins were both vulnerable to quantum computing and linked to wallet addresses with publicly visible cryptographic keys.
At current prices, that equates to nearly $730 million — a sum the company described as resembling routine trading and not a market crisis.
A steel frame takes shape in Chicago
The discovery comes at a delicate time. This week, PsiQuantum co-founder Peter Shadbolt posted a photo on X showing the Chicago construction site where his company is building what it calls the world’s first commercially useful quantum computer.
In six days, workers erected 500 tons of steel. The structure will house a machine capable of running 1 million qubits – a unit of quantum computing power.
Scientists say the capacity is, in theory, enough to crack the type of encryption protecting Bitcoin wallets.
It’s time to build really big quantum computers. Five hundred tons of steel in six days. The delivery date of the cryoplant is blowing our minds. Grateful to the hundreds of people engaged in this mission pic.twitter.com/eqSwsESusK
– Pete Shadbolt (@PeteShadbolt) March 5, 2026
The company raised $1 billion for the project, announced in September, with chipmaker Nvidia as a key partner.
PsiQuantum says the facility is designed to support fault-tolerant quantum computing and serve as an infrastructure for next-generation AI systems.
As a reminder, the largest quantum computer currently in operation at the California Institute of Technology works with 6,100 qubits. A jump to 1 million represents an unprecedented scale in the field.
What would really be at risk?
Bitcoin encryption relies on 256-bit cryptographic keys. A preliminary paper published last month estimates the number of qubits needed to crack 2,048-bit keys at around 100,000, suggesting that a million-qubit machine could, mathematically, get the job done.
But experts have long noted that the raw number of qubits is only part of the equation. Equally important are error rates and system stability.
BTCUSD trading at $68,470 on the 24-hour chart: TradingView
Not all Bitcoin wallets are equally exposed. Coins held at addresses that have never transacted – known as unspent transaction outputs, or UTXOs – are considered most at risk, particularly those whose public keys have been exposed on the blockchain. Many of these wallets date back to the early days of Bitcoin.
Developers are already working on a fix
Bitcoin developers debate how to respond. One option being considered is a hard fork – a fundamental change in the network code – to introduce post-quantum cryptography.
A co-author of BIP-360, a proposal to make Bitcoin quantum-resistant, said the upgrade could take up to seven years to be fully implemented.
PsiQuantum, for its part, said it has no plans to use its technology to attack Bitcoin. Co-founder Terry Rudolph made this point publicly at a Bitcoin quantum summit last July.
Experts in the field say a real quantum threat to Bitcoin is still at least a decade away.
For now, construction continues in Chicago – 500 tons of steel and counting.
Featured image from Unsplash+/Alex Shuper, chart from TradingView
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