AI infrastructure investment is transforming blockchain networks from transaction systems into coordination layers for compute, data, identity, and autonomous agents. Pantera Capital has estimated that Alphabet, Amazon, Meta, and Microsoft are projected to spend around 650 billion USD on AI infrastructure in 2026. One sign of the shift is the migration from crypto mining to AI hosting: IREN signed a 3.4 billion USD GPU cloud services deal with NVIDIA for AI workloads, and Hut 8 signed a 352 MW lease for a Texas campus focused on AI infrastructure. A 2024 academic review of AI and blockchain research noted concrete uses of machine learning for public chains, including Bitcoin address clustering, illegal transaction prediction, exchange and miner classification, and fraudulent Ethereum. Blockchain security is becoming AI-assisted by default, enabling continuous analysis across wallets, contracts, bridges, and exchanges.