A new report from digital asset manager CoinShares is pushing back on the growing narrative that bitcoin is facing an imminent quantum computing crisis, arguing that only a small fraction of the supply is realistically at risk in a way that could move markets.
CoinShares is the fourth largest manager of digital asset exchange-traded products globally behind BlackRock, Grayscale and Fidelity and has a self-reported 34% market share of EMEA. It had over $10 billion in assets under management as of September 2025.
Saturday’s report challenged widely cited estimates suggesting that as much as 20% to 50% of all bitcoin could eventually be vulnerable to quantum-enabled key mining. These numbers, CoinShares said, blur the line between theoretical exposure and coins that could actually be compromised at scale.
CoinShares narrowed its focus to legacy Pay-to-Public-Key (P2PK) addresses, where public keys are permanently visible on-chain and therefore easier targets if quantum computers become able to reverse them.
The firm estimates that around 1.6 million BTC – or around 8% of the total supply – are sitting in these older address types.
But CoinShares argued that the number of coins large enough to cause “noticeable market disruption” if stolen is far less: around 10,200 BTC. The rest, it said, is spread over more than 32,000 UTXOs averaging about 50 BTC each, making them far less attractive and far more time-consuming to crack even under optimistic assumptions.
The key point is that most of the potentially exposed bitcoin isn’t sitting in a handful of giant, juicy targets. It is spread over more than 32,000 separate chunks of coins, and each chunk averages around 50 BTC.
A quantum attacker would have to crack these chunks one by one to steal them, rather than breaking into a single address and walking away with a market-moving move. It makes work slower, noisier and less profitable, even assuming the attacker has exceptionally strong quantum hardware.
CoinShares said breaking bitcoin’s cryptography would require fault-tolerant quantum systems about 100,000 times more powerful than the largest machines today, placing the threat at least a decade away. Ledger CTO Charles Guillemet, quoted in the report, noted that Google’s Willow is a 105-qubit machine, while key breaking would require millions of qubits.
Instead, the firm endorsed a gradual transition to post-quantum signatures, framing quantum risk not as an emergency but as a predictable engineering problem bitcoin can absorb over time.
Quantum fears are not new to bitcoin, but they have crept back into market conversations as prices falter and investors look for structural risks to blame.
In December, CoinDesk reported that most bitcoin developers view quantum computers as a distant, non-issue, arguing machines capable of cracking bitcoin’s cryptography likely won’t exist for decades.
Critics counter that the real problem isn’t the timeline, but the lack of visible preparation, especially as governments and big tech companies begin to roll out quantum-resistant systems.
Proposals like BIP-360 aim to introduce new wallet formats that could allow users to migrate gradually, but the debate has highlighted a growing divide between developers and increasingly institutional capital that wants a clearer long-term plan.
