I see he created one of the world's first Index funds in 1971, four years before Vanguard was founded (1975).
He points out that while it's easy to spot a stock bubble, it's nearly impossible to know when the bubble will end. That's the problem we currently have with the AI - Mag 7 bubble. Everyone knows it's a bubble, but when does the air come out? Who knows, but AI is now starting to wreck entire sectors (software) by making them obsolete. And AI may have a similar effect on various financial services sectors. So AI could be a bubble that continues to inflate, while simultaneously deflating the rest of the market / economy.
Market Data 
Markets 
AI
