More than a third of all Bitcoin in existence now sits behind publicly visible keys that a sufficiently powerful quantum computer could one day target, according to new data from on-chain analytics firm Glassnode reported on 11 and 12 November 2026.

Glassnode said in an update on 10 November 2026 that 7.12 million Bitcoin, or 35.4% of the network's total issued supply, have public keys already visible on the blockchain. At current market prices, those holdings are worth more than $500 billion, according to CryptoNews, which reported the figures on 12 November 2026.

Exposure has grown sharply since May

The scale of the exposure has risen quickly. An earlier Glassnode snapshot put exposed Bitcoin at 6.04 million coins, or 30.2% of supply, on 20 May 2026. The latest reading is therefore 1.08 million Bitcoin higher, a rise of 5.2 percentage points in less than six months, according to CryptoNews.net.

Independent data points in the same direction. ChainQuery put exposed supply at around 35.6% in early November 2026, close to Glassnode's reading, according to a TradingView report on the Glassnode data.

Address reuse is the largest driver. Glassnode attributes 25.8% of total supply to wallets where earlier transactions have already revealed the public key. Exchange holdings account for 11.6% of supply, but that figure forms part of the address-reuse total rather than adding to it, so the two percentages should not be added together.

Early pay-to-public-key outputs, a format that records the public key directly, hold approximately 1.71 million Bitcoin, with a significant share attributed to Bitcoin's creator, Satoshi Nakamoto, according to the TradingView report.

A future risk, not a theft

It is important to be clear about what the figures do and do not show. No Bitcoin has been stolen, and no quantum computer in existence today can break Bitcoin's current cryptography. The concern centres on Shor's algorithm, which could in theory allow a sufficiently powerful quantum computer to derive a private key from a publicly available one. There is no settled timeline for when, or whether, such machines will arrive.

Glassnode's co-founder Rafael Schultze-Kraft pointed to a straightforward fix for the largest category of exposure: moving coins from reused addresses to freshly generated ones eliminates the exposure tied to reuse. Bitcoin developers are also exploring longer-term answers. BIP 360, a draft Bitcoin Improvement Proposal, proposes new transaction structures designed to reduce public-key exposure, while BIP 361 outlines a possible migration away from vulnerable signature schemes. Both remain drafts.

Price steadies near $73,700

The quantum warning comes as Bitcoin trades cautiously after a sharp correction. The cryptocurrency recovered from its 10 November low of $72,600 to reach around $74,000, before easing to $73,700 on the morning of 12 November 2026, according to CryptoNews.

Sentiment remains fragile. US spot Bitcoin exchange-traded funds recorded around $1.58 billion in net outflows across the seven completed trading sessions through 10 November, according to market experts cited by CNBC TV18 on 12 November 2026, as hotter-than-expected US inflation strengthened expectations of another Federal Reserve rate rise in December.

For holders, the Glassnode data is a reminder that Bitcoin's long-term security depends not only on price, but on how coins are stored. Moving funds held at reused addresses to fresh ones is, on Glassnode's own account, the simplest step available today, while the wider debate over quantum-resistant Bitcoin continues.