Quantum threats are not tomorrow's matter, but address reuse is indeed today's matter.

Glassnode research shows that currently, 6.04 million BTC have exposed public keys on the blockchain, accounting for approximately 30.2% of the total issued supply, theoretically posing a future risk of quantum computing attacks; 13.99 million BTC do not have exposed public keys. Exposure is divided into structural (1.92 million, 9.6%) and operational (4.12 million, 20.6%, mainly due to address reuse). Among operational exposure, exchange BTC accounts for 1.66 million, or 8.3% of the total supply, roughly 40% of all unsafe operational BTC. These results should not be interpreted as risk rankings or solvency signals for individual companies.