A joint white paper by ARK Invest and Unchained reveals that approximately 34.6% of Bitcoin's supply is at long-term risk from quantum computing breakthroughs, while 65.4% remains relatively secure. The vulnerable assets include around 5 million BTC that can be moved due to address reuse, 1.7 million BTC in early P2PK addresses, and 200,000 BTC in P2TR addresses. The report emphasizes the need for Bitcoin to integrate post-quantum cryptography standards like ML-DSA or SLH-DSA through a soft fork upgrade. Additionally, the BIP-360 proposal suggests introducing Pay-to-Merkle-Root output types to mitigate Taproot's key path vulnerabilities. ARK projects that quantum computers may not be able to crack the first public key until the mid-2030s.