Willy Woo, an onchain analyst and early adopter of Bitcoin, says growing concerns around quantum computing are beginning to weigh on Bitcoin’s long-term investment thesis relative to gold.
In a post on X on Monday, Woo argued that markets are starting to factor in the possibility of a future “Q-Day” — a hypothetical point at which quantum computers become powerful enough to break current public-key cryptography.
Woo pointed to an estimated 4 million “lost” BTC — coins believed to be inaccessible due to missing private keys — that could theoretically be recovered if quantum machines were able to derive private keys from exposed public keys. Such a scenario, he said, would challenge part of Bitcoin’s scarcity narrative.
He estimated there is roughly a 25% chance the network would agree to freeze those coins through a hard fork — a move that would rank among the most contentious governance decisions in Bitcoin’s history.
Q-Day risk and “lost” coins
Blockchain researchers estimate that the 4 million exposed coins account for about 25% to 30% of the total Bitcoin supply. These funds sit in addresses with publicly visible keys, making them among the most vulnerable in a potential quantum attack scenario.
However, freezing those coins would disrupt long-standing principles around fungibility, immutability and property rights. The debate could split the community between those favoring backward-compatible upgrades that preserve existing rules and balances, and those willing to alter the protocol more radically to shield early-era holdings.
With what Woo describes as a 75% probability that the coins remain untouched, investors should still account for a meaningful chance that a volume of BTC equivalent to roughly eight years of corporate accumulation could re-enter circulation.
According to Woo, this risk is already being reflected as a structural discount in Bitcoin’s valuation relative to gold over a five- to 15-year horizon, potentially weakening Bitcoin’s historical trend of gaining purchasing power when measured against the precious metal.
Bitcoin’s post-quantum migration path
Many core developers and cryptographers maintain that Bitcoin is not facing an imminent existential threat and would have time to adapt if quantum computing advances accelerate.
Rather than a sudden emergency hard fork, the emerging vision for a post-quantum transition involves a phased migration. Over several years, the network could gradually move users toward new address formats and upgraded key management standards designed to withstand quantum attacks.
Even in a scenario where quantum capabilities materialize sooner than expected and previously “lost” coins become accessible, some Bitcoin advocates argue a market dump is unlikely. Alex Gladstein, chief strategy officer at the Human Rights Foundation, has suggested a more plausible outcome would see such coins quietly accumulated by a nation-state rather than rapidly sold into the market.
Quantum risk enters the macro conversation
Woo’s warning comes at a time when Bitcoin is trading nearly 50% below its all-time high, and quantum risk has shifted from a fringe technical debate to a topic of discussion in institutional asset allocation.
In January, Jefferies strategist Christopher Wood removed Bitcoin from his flagship Greed & Fear portfolio and reallocated the position to gold. Wood explicitly cited concerns that “cryptographically relevant” quantum machines could undermine Bitcoin’s long-term store-of-value appeal for pension-style investors.
