Speculative manias, like the AI boom, function like collective hallucinations. The overwhelming belief in future demand becomes self-fulfilling, attracting capital that builds tangible infrastructure (e.g., data centers, fiber optic cables) long before cash flows appear, often leaving lasting value even after the bubble bursts.

Jeremy Grantham explains that the biggest bubbles (railroads, internet, AI) are not scams. They are fueled by genuine belief in a world-changing technology, which leads to massive over-investment and an eventual, inevitable collapse.

Today's massive AI company valuations are based on market sentiment ("vibes") and debt-fueled speculation, not fundamentals, just like the 1999 internet bubble. The market will likely crash when confidence breaks, long before AI's full potential is realized, wiping out many companies but creating immense wealth for those holding the survivors.

Following George Soros's theory of reflexivity, markets act like thermostats, not barometers. Rising AI stock prices attract capital, which further drives up prices, creating a self-reinforcing loop. This feedback mechanism detaches asset values from underlying business fundamentals, inflating a bubble based on pure belief.

Bubbles are created when assets like startup equity are valued astronomically, creating immense perceived wealth. However, this "wealth" is not money until it's sold. A crash occurs when events force mass liquidation, revealing a scarcity of actual money to buy the assets.

The dot-com era was not fueled by pure naivete. Many investors and professionals were fully aware that valuations were disconnected from reality. The prevailing strategy was to participate in the mania with the belief that they could sell to a "greater fool" before the inevitable bubble popped.

Drawing from botany, this concept argues that market participants (like weeds) evolve to mimic the traits currently being rewarded (like crops), regardless of underlying substance. Companies adapt narratives to fit prevailing success templates (e.g., AI, dot-com), creating bubbles when mimicry overtakes fundamentals.

Contrary to popular belief, the most dangerous speculative bubbles aren't con jobs. They are built on universally recognized, transformative ideas like railroads, the internet, or AI. Widespread belief in their world-changing potential is precisely what fuels the speculative mania and subsequent crash, as everyone wants a piece of the future.

The root cause of market bubbles isn't the new technology itself, but recurring human behaviors like greed, optimism, and social proof. Technology is merely the narrative vehicle for these powerful psychological tendencies that have existed for centuries.