A wave of giant AI and tech IPOs — SpaceX, OpenAI, and Anthropic — is shaping up to look like a market top, which is bad news for investors buying in at peak excitement.

• Together these three IPOs would raise as much money, adjusted for inflation, as every dot-com IPO of 2000 combined.
• History shows a pattern: Xerox, Ford, McDonald's, Apple, Goldman Sachs, and Blackstone all went public when investor demand was hottest, and the market peaked right after.
• Past bubbles were easy to spot because price-to-earnings ratios went wild, with unprofitable companies trading at hundreds of times what they earned.
• This time valuations look fairly reasonable, and that is what makes the AI bubble potentially more dangerous — the warning signs are hidden.

Outlook: If the pattern holds, the flood of mega-IPOs could mark the peak of the AI boom rather than the start of it.