As of October 2026, Bitcoin had fallen nearly 35% from its October 2025 high, Ethereum over 50%, and Solana and XRP each 65%, partly attributed to quantum computing risks.

The first and largest cryptocurrency, spanning its price and adoption, mining, protocol politics, and its contested role as digital money and inflation hedge.

Whether quantum computers could break the cryptography securing Bitcoin and other blockchains, and how networks plan to migrate before that day.