Michael Saylor, executive chairman of Bitcoin-heavyweight firm Strategy (formerly MicroStrategy), has publicly criticized the practice of publishing on-chain proof-of-reserves (PoR), calling it a “bad idea” that poses serious security risks to institutions, custodians, exchanges, and investors alike.
Speaking at the Bitcoin 2025 conference in Las Vegas on May 26, Saylor responded to a question about the growing adoption of PoR in the crypto industry. “The current, conventional way to publish proof of reserves is an insecure proof of reserves,” he stated. “It actually dilutes the security of the issuer, the custodians, the exchanges and the investors. It’s not a good idea, it’s a bad idea.”
Proof-of-reserves became popular after the collapse of major exchanges like FTX and Mt. Gox, with the aim of assuring customers that their assets were actually being held and were not being misused. Firms such as Binance, Kraken, OKX, and Bitwise embraced this transparency standard as a way to build trust. However, Saylor believes the approach may be dangerously flawed.
When asked whether Strategy would publish its own proof-of-reserves, Saylor chose not to respond directly. Instead, he emphasized that exposing wallet addresses and on-chain data could open institutions to surveillance, tracing, and potential hacks. “No institutional-grade or enterprise security analyst would think it’s a good idea to publish all of the wallet addresses, such that you could be traced back and forth,” he said. “Go to AI, put it in deep think mode and then ask it ‘what are the security problems of publishing your wallet addresses?’ It would write 50 pages of security problems.”
Beyond the risks of data exposure, Saylor also warned that proof-of-reserves often gives a misleading impression of solvency. “They only show one side of the picture—what the company holds—not what they owe.” Without disclosing liabilities, companies can present a skewed version of their financial health.
Saylor’s comments carry weight in the industry. Strategy is currently the largest corporate holder of Bitcoin in the world, owning 576,230 BTC—valued at over $62.6 billion. The company’s accumulation strategy has positioned it as a bellwether for institutional Bitcoin adoption.
While transparency in crypto remains a noble pursuit, Saylor’s remarks are a reminder that not all methods of achieving it are without consequence. The industry now faces the challenge of finding ways to verify solvency and build trust—without opening the door to new threats.
