Just over 10,000 Bitcoin — out of nearly 20 million in circulation — sits in wallets actually exposed to a quantum attack. That number comes from CoinShares, a crypto asset management firm, which found in February that only 10,230 coins are both vulnerable to quantum computing and tied to wallet addresses with publicly visible cryptographic keys. At current prices, that amounts to close to $730 million — a sum the firm described as resembling a routine trade, not a market crisis. A Steel Frame Takes Shape In Chicago The finding lands at an awkward moment. This week, PsiQuantum co-founder Peter Shadbolt posted a photo to 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 had 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 that capacity is, in theory, sufficient to crack the type of encryption protecting Bitcoin wallets. Time to build really big quantum computers. Five hundred tons of steel up in six days. Cryoplant delivery date breathing down our neck. Grateful to the many hundreds of people locked in to 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 infrastructure for next-generation AI systems. For context, the largest quantum computer currently operating at the California Institute of Technology runs on 6,100 qubits. A jump to 1 million represents a scale that has no precedent in the field. What Would Actually Be At Risk Bitcoin’s encryption relies on 256-bit cryptographic keys. A preprint paper published last month put the number of qubits needed to break 2048-bit keys at around 100,000 — suggesting that a 1 million-qubit machine could, mathematically, do the job. But experts have long noted that raw qubit count is only part of the equation. Error rates and system stability matter just as much. Not all Bitcoin wallets face equal exposure. Coins held in addresses that have never made a transaction — 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 those wallets date back to Bitcoin’s earliest days. Developers Are Already Working On A Fix Bitcoin developers have been debating how to respond. One option on the table is a hard fork — a fundamental change to the network’s code — to introduce post-quantum cryptography. A co-author of BIP-360, a proposal aimed at making Bitcoin quantum-resistant, said that the upgrade could take as long as seven years to fully implement. PsiQuantum , for its part, has said it has no intention of using its technology to attack Bitcoin. Co-founder Terry Rudolph made that point publicly at a Bitcoin quantum summit last July. Experts in the field say a genuine 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
