The invisible force behind all of this is no mystery to anyone paying attention to the city's tech economy. San Francisco is home to some of the most valuable private companies in the world, and their employees have been quietly accumulating — and, increasingly, cashing out — fortunes.

Earlier this week, five people who touch every layer of the AI supply chain sat down at the Milken Institute Global Conference in Beverly Hills, where they talked with TechCrunch…

The invisible force behind all of this is no mystery to anyone paying attention to the city's tech economy. San Francisco is home to some of the most valuable private companies in…