$9 billion bitcoin sale by a single Galaxy client reignites quantum debate

A single Galaxy Digital (GLXY) client sold $9 billion worth of bitcoin last year, and quantum computing may have been the reason for it.

The sale, CEO Mike Novogratz said during the company’s Q4 2025 earnings call, helped drag crypto markets as the position took time to unwind. It came from a Satoshi-era investor as an estate planning move.

“It’s like distributing an IPO, price usually goes down then the distribution ends, it goes back up,” Novogratz said after revealing a single customer sold $9 billion worth of bitcoin. “I think that’s the part of the cycle we’re in right now. As I said earlier, I don’t know when the seller’s exhaustion happens. There’s not that much leverage in the system anymore.”

Novogratz implied the decision to sell was part of a broader wave of profit-taking by early bitcoin adopters that the company has been seeing. While the community has long championed “HODLing” through volatility, that conviction appears to be weakening.

“There were a tremendous amount of these religious believers in this concept of HODLing and not letting go of your bitcoin ,” he said. “And somehow that fever broke and you started seeing some selling.”

While the sale isn’t new and was reported last year, it was seen as symbolic, igniting a debate among bitcoin’s OG holders about losing faith. What caught everyone’s attention now is the possibility that the reason was the risk posed by quantum computing to bitcoin.

‘Big excuse’

Novogratz called the quantum threat the “big excuse” being used for the sale. The crypto industry, he said, has expected quantum technology to be a threat.

And he isn’t wrong, in recent times the debate has been heating up. Investors and industry observers alike are now weighing the real threat of quantum breaking Bitcoin’s encryption.

While some say quantum computing technology is still a long way from becoming a reality, some developers have argued that as we get closer to quantum threats, the Bitcoin network will need to be upgraded to become quantum-resistant. The risk, however, is that “developers all get obstinate and they fight amongst each other,” Novogratz said, although noting that’s an unlikely scenario.

“I just don’t see that happening. In the long run, quantum will not be a big issue for crypto,” he said. “It’ll be a big issue for the world but crypto, and Bitcoin especially will be able to handle it.”

Still, the break from the idea that one should hold on to their bitcoin forever, Novogratz mentioned, could be rooted in something deeper than the market’s current bearish trend.

Cardano founder Charles Hoskinson has in the past highlighted Cardano’s proactive push for quantum-resistant upgrades, while early Bitcoin developer Adam Back has pointed to ongoing R&D on secure cryptographic schemes for Bitcoin.

To the CEO of Bitcoin technology firm JAN3, Samson Mow, quantum would first be a threat to the banking industry. Still, the Ethereum Foundation has just this month formally elevated post-quantum security to a strategic priority with the creation of a dedicated Post-Quantum team.

The quantum threat

Maybe one of the bigger stories on the threat that made a splash is that Coinbase has acknowledged that quantum computing could be a real, long-term threat to the cryptocurrency market, as Shor’s algorithm could break the signatures protecting the private keys of bitcoin addresses.

That would essentially allow bad actors to leverage quantum computers to access funds in any wallet whose public keys — often compared to an International Bank Account Number (IBAN) in crypto — are already exposed on the blockchain.

Modern Bitcoin addresses hash their public keys, concealing them until funds are spent on the blockchain. This means that around one-third of bitcoin’s supply is estimated to be under threat from quantum computers.

Another threat, Grover’s algorithm, could outcompete the computing power protecting the network, disrupting Bitcoin’s economic and security model.

The threat, however, isn’t imminent. Current quantum computers aren’t at 1,000 qubits — the unit used to measure the power of quantum computers — while millions are estimated to be necessary to compromise Bitcoin’s cryptography.

The threat is nevertheless producing real-world consequences for Bitcoin.

Jeffries’ global head of equity strategy, Christopher Wood, last month removed a 10% allocation to bitcoin from his model portfolio due to the threat quantum computing poses.