The company’s AI investment has obliterated free cash flow, and analysts now worry that Zuckerberg has no plan to turn his AI investment into returns. Beyond the headlines, I see four main categories of risk facing AI, or four horsemen of the potential AI bubble apocalypse. They include spending risk, revenue risk, political risk, and technological risk. AI defenders used to say, “Don’t worry about an AI bubble, because the richest companies in the world can fund it with cash flow from normal operations.” For years, AI advocates could correctly point out that AI was different, because the project was almost entirely funded with free cash flow.