Tom Lee, co‑founder of Fundstrat, has stated that sufficiently powerful quantum computers might break Bitcoin protections by 2028–2029. He added that the sector currently lacks a unified response plan.

Scope of the vulnerability

Lee estimates that 30–35% of circulating bitcoin could be at risk, which corresponds to approximately ~7 million coins. This pool reportedly includes roughly ~1 million coins associated with Satoshi Nakamoto.

• A key concern is legacy addresses with already exposed public keys that could enable private key recovery by a quantum attack.
• If a quantum device derived private keys from public keys, coins on those addresses would be susceptible to theft.

Community responses

Adam Back, creator of Hashcash, criticized Lee’s characterization and urged caution in framing the issue. He noted that Bitcoin does not encrypt coins at spend time, relying instead on ECDSA signatures and seed phrases.

Back argued that brute‑force recovery of seed phrases would remain infeasible even for quantum systems, and emphasized the difference between signature schemes and brute‑force threats.

Comparative resilience and mitigation

Lee contrasted Bitcoin with platforms such as Ethereum and Solana, suggesting those networks benefit from more flexible upgrade cycles that could enable faster cryptographic transitions if required.

He also warned that without coordinated industry action, migration to quantum‑resistant primitives may be uneven, leaving substantial value exposed during any transition period.

Implications for holders and developers

Developers and custodians may need to prioritize migration strategies for legacy addresses and consider rollouts of post‑quantum signature schemes. Coordination across wallets, exchanges and protocol teams would reduce fragmentation risks.

Lee’s timeline places urgency on research and preparedness, while differing expert views highlight debate over the immediacy and technical pathways for mitigation.