The largest risk for Bitcoin (BTC) in the event of a quantum computing breakthrough is the potential adaptation window to become resistant, VanEck’s head of digital assets research Matt Sigel wrote in a June 2 post on X.
He said banks, tech platforms, and other blockchains face the same cryptographic weakness as Bitcoin does in the context of post-quantum computing. Yet, most can patch their servers once post-quantum standards clear the National Institute of Standards and Technology process.
Sigel noted that custodians, exchanges, and even Ethereum (ETH) could introduce lattice- or hash-based signature schemes behind the scenes. Central control allows them to rotate keys and roll out patches without community input. Bitcoin lacks that lever.
‘Window of uncertainty’
Despite believing in the ability of Bitcoin to adapt in the long run, Sigel highlighted that miners, node operators, and wallet providers must decide to run code deployed by core developers.
That coordination historically spans years, as seen with SegWit and Taproot. “Any upgrade would require careful coordination across the community,” Sigel wrote, adding that some users already test post-quantum wallets, yet no broad agreement exists.
Because full-scale quantum hardware may arrive with little warning, Sigel identifies the primary hazard as the period between the first credible demonstration and Bitcoin’s network-wide migration to a new signature scheme.
He warned:
“Even a single high-profile theft could cause market volatility and trigger a scramble to upgrade.”
The analyst added that VanEck has begun studying quantum-computing equities in one of its internal funds, and the firm’s European arm launched a Quantum Technologies UCITS ETF last week, which tracks hardware and software vendors.
Furthermore, Sigel referred to Elon Musk’s recent announcement that X will feature “Bitcoin-level encryption.”
Sigel wrote that Musk may reference Bitcoin Improvement Proposals 151 and 324, which encrypt peer-to-peer traffic but do not alter signature math. He said the remark shows Bitcoin’s present model still rates as strong until quantum machines cross the threshold.