🌊Jeremy Grantham’s Warning Is Not About AI. It Is About the End of Autumn.
🫧The crash is already here — not because technology has failed, but because the financial system has overcapitalized the future again.
Jeremy Grantham’s latest warning is easy to misunderstand.
The headline says: “I’m Selling. The Crash Is Already Here.”
Most people will hear that and immediately reduce it to a market call.
They will ask:
“Is he bearish on AI?”
“Is he saying Nvidia is a short?”
“Is he calling the top?”
“Is this another billionaire doom prediction?”
That misses the point.
Grantham is not saying AI is fake.
He is saying the opposite.
He believes artificial intelligence is one of the defining technologies of the modern era, comparable to the railroads and the internet. He says great bubbles do not usually form around worthless ideas. They form around the most important ideas, because those are the ideas people can most easily extrapolate into infinity.
That is the key.
The greatest bubbles are not built on nothing.
They are built on truth carried too far.
And that is exactly how LongWave Autumn ends.
The LongWave Context: Autumn Always Mistakes the Future for an Asset Class
In Kondratieff’s LongWave framework, the final stage, Autumn, is the age of financialization.
Autumn is not the beginning of prosperity.
It is the capitalization of past prosperity.
It is when societies stop building wealth primarily through production and begin manufacturing the appearance of wealth through:
Falling interest rates
Rising asset values
Expanding credit
Financial engineering
Speculative narratives
Concentrated market leadership
Leverage disguised as confidence
This is why late Autumn always feels brilliant at the top.
The towers are the highest.
The markets are richest.
The billionaires are most visible.
The promises are largest.
The technology appears miraculous.
But beneath the surface, the system is becoming fragile.
Autumn says:
“The future is so bright that any price is justified.”
Winter answers:
“No. Price still matters.” ❄️
That is Grantham’s argument in one sentence.
Grantham’s Core Insight: The Technology Can Win While Investors Lose
The most important idea in the transcript is this:
AI can change the world, and AI investors can still lose a fortune.
That sounds contradictory to most people, who confuse technological success with investment success.
They are not the same thing.
Railroads changed the world.
Railroad investors were often destroyed.
The internet changed the world.
Dot-com investors were often destroyed.
Amazon inherited the retail world, but its stock fell roughly 90% from its 2000 peak before becoming one of the great companies of the modern era. Grantham uses Amazon as the perfect example: the idea was right, but the price was wrong.
That is the essence of Schumpeter’s creative destruction. 🔥➡️🌱
The innovation survives.
The capital structure does not.
The productive technology moves into the next economic spring.
The speculative investors who overpaid in Autumn get wiped out before the renewal arrives.
This is why the phrase “AI is real” does not settle the market question.
Of course, AI is real.
The real question is:
How much of the next 20 years of productivity has already been pulled forward into today’s stock prices?
That is where Grantham becomes dangerous to the consensus.
Bubbles Are Not Usually Built on Lies. They Are Built on Overextrapolated Truths
Grantham’s historical framework is very clear.
