Andreessen Horowitz

a16z's AI infrastructure portfolio is the broadest in venture — across compute silicon, energy generation, grid software, and the AI model layer. They've backed Helion (fusion), multiple SMR-adjacent companies, and a wave of grid-orchestration software plays. The bet isn't on a single winner but on owning the picks-and-shovels of the entire stack.

Their thesis is more about pace than specific calls — getting capital into every layer of the stack early. Watch for follow-on rounds and bridge financings in the existing portfolio; those signal where they're seeing breakout traction.