The Diary Of A CEO
Billionaire's WARNING: I'm SELLING. The Crash Is Already Here!
Summarised with Bite · 19 min read
Jeremy Grantham, the veteran investor who says he spent roughly 60 years in markets and once helped manage $165 billion, delivers a blunt warning: US stocks, especially AI-linked and high-flying tech names, look like a historic bubble, and ordinary people should stop assuming the S&P 500 is the safest default. But the conversation gets broader and stranger in a useful way, connecting market bubbles, inequality, social breakdown, toxic chemicals, fertility decline, and AI risk into one thesis: modern society is running on optimism while ignoring systems that are quietly fraying.
0:00 – 6:45
Why the biggest ideas create the biggest crashes
The interview opens with a jolt. Asked what average people should do with their salary, Grantham does not hedge. "Don't own US stocks." Then he doubles down: if you have a big position in US technology stocks, "sell them all." Crypto gets even less mercy. He calls it "an unnecessary piece of nonsense" and says Bitcoin will "certainly go to zero." That harshness makes more sense once he explains the lens he has used for decades. He says humans are wildly short term and structurally optimistic. People want good news. They want smooth compounding. But he thinks that idea is fantasy on a finite planet, quoting economist Kenneth Boulding: "The only people who think you can have compound growth on a finite planet are madmen and economists." That line is the key to everything that follows. Grantham's central point is unexpectedly simple: bubbles are not built on fake ideas. They form around the most important ideas. Railroads changed the world. The internet changed the world. But because everyone could see that, everyone rushed money in at once. The world got overbuilt before the economics made sense. Then prices collapsed. He uses Amazon as the perfect memory hook. In 1999, Amazon rose "six or seven times." In the tech crash, it fell "92%." His phrase is memorable because it captures the whole pattern: out of the wreckage, Amazon still inherited retail. That is why he thinks AI is dangerous as an investment even if it is revolutionary as a technology. He calls it "one of the defining great ideas of the last couple of hundred years," right up there with railroads. And precisely because it is so important, he thinks it may produce the biggest bubble in American history. He says the timing could be "the next few days, the next few weeks, the next few months, but certainly the next few years." In other words, he is not saying AI is fake. He is saying the more obvious and world-changing an idea is, the easier it becomes for investors to overpay for it.
4 more sections in the app
- 6:45 – 25:42What a bubble feels like before it breaks
- 25:42 – 39:59Why the people paid to warn you rarely will
- 42:01 – 1:00:16AI could enrich the world, and still make it more dangerous
- 1:00:16 – 1:44:49The crash he fears is not only financial, it is social and biological
