Glassnode reports that 6.04 million Bitcoin, representing 30.2% of the circulating supply, are at risk of exposure to quantum computing threats. This exposure arises because the public keys for these coins are already visible on-chain, making them vulnerable to potential future quantum attacks. The exposed Bitcoin is valued at over $452 billion based on current market prices. The report categorizes the exposure into structural and operational risks. Structural exposure, accounting for 1.92 million BTC, involves vulnerabilities inherent in Bitcoin's script design, such as early Pay-to-Public-Key outputs and Taproot outputs. Operational exposure, totaling 4.12 million BTC, stems from wallet management practices that reveal public keys, with exchange-related balances contributing significantly to this risk. Despite these concerns, Glassnode notes that 13.99 million BTC remain protected as their public keys are not yet visible on-chain. The report emphasizes that while current computing systems cannot derive private keys from public keys, future quantum advancements could change this, highlighting the importance of public-key visibility in assessing Bitcoin's security against quantum threats.