New research reveals the number of quantum-exposed Bitcoins

An on-chain Glassnode analysis finds roughly 6.04 million BTC (30.2% of issued supply) have publicly visible public keys at rest and are therefore theoretically susceptible to future quantum attacks. The exposure splits into 1.92m BTC (9.6%) structural risk from legacy output types and 4.12m BTC (20.6%) operational risk from practices like address reuse and partial UTXO spending; exchanges hold about 1.63–1.66m BTC of the operationally exposed balance. The study is a data snapshot rather than a threat timeline—it does not predict when quantum attacks could be practical—but it may increase focus on custodial practices, wallet hygiene, and protocol upgrades to reduce systemic exposure. Overall the finding is informational and highlights potential long-term security considerations rather than an immediate market shock.