Analyst CryptoQuant Maartunn detected a major on-chain transaction in which 500 $BTC, which had remained completely dormant for more than 10 years, were moved to a new address for the first time. On the Spent Output Age Bands chart for 10-year-old Bitcoin, this activity appeared as an isolated green spike.
The transfer of such an old wallet coincided with the release of major research and news in the quantum technology sector, namely Glassnode’s report on Bitcoin’s quantum security. According to analysts, 30.2% (6.04 million $BTC) of the total market supply is already potentially vulnerable to future quantum attacks.
500 $BTC that hadn’t moved in 10 years just moved. 👀 pic.twitter.com/A3tF3YIiK3
— Maartunn (@JA_Maartun) May 20, 2026
Is the quantum threat forcing whales to act?
The vulnerability is tied to exposed public keys on addresses from the Satoshi Nakamoto era and poor wallet hygiene, including address reuse and custodial storage practices. A quantum computer could hypothetically derive a private key only where the public key has already been exposed on-chain.
Exchanges account for around 1.66 million $BTC within this risk category. Approximately 5% of Coinbase-held $BTC is considered vulnerable, compared to around 85% for Binance and nearly 100% for Bitfinex.
At the same time, the computing industry is demonstrating clear progress and moving beyond the purely laboratory stage. By the end of May 2026, Saudi Aramco, together with Pasqal, had launched cloud access in Saudi Arabia to the country’s first quantum computer featuring 200 programmable qubits through the QCaaS platform.
Against this backdrop, IBM declared the beginning of the era of “quantum utility”, with plans to achieve quantum advantage by the end of 2026 and build the fault-tolerant Quantum Starling system by 2029.
Statements from specialists such as Scott Aaronson, who warned that cryptographic systems could face realistic hacking threats by 2029, no longer appear like distant speculation to early Bitcoin investors.
As Blockstream creator Adam Back notes, Bitcoin must prepare for the quantum threat in advance through the implementation of optional upgrades, but large long-term holders appear to have decided to play it safe and have already started moving their $BTC.
