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.

Contrary to the belief that bubbles are based on hype, Gurley asserts they are a byproduct of a real technological breakthrough. The initial, genuine value attracts talent and capital, which then draws in speculators and 'fools' who create the bubble. The underlying technology's reality is the catalyst.

Citing theorist Carlotta Perez, Gurley argues that only genuinely transformative technologies create bubbles. The rapid wealth creation from the real innovation attracts speculators and charlatans, which inflates the bubble. Therefore, a bubble is evidence of a real shift, not a sign the technology is fake.

History shows that transformative technologies like railroads and the internet often create market bubbles. Investors can lose tremendous amounts of capital on overpriced assets, even while the technology itself fundamentally rewires the economy and creates massive societal value. The two outcomes are not mutually exclusive.

The Railway Mania of the 1840s proves that a world-changing technology can still lead to a catastrophic investment bubble. Despite railways transforming society, massive over-investment and hype caused an 85% collapse in share prices, wiping out fortunes and illustrating the danger of investing in frenzied sectors.

A genuine technological wave, like AI, creates rapid wealth, which inherently attracts speculators. Therefore, bubble-like behavior is a predictable side effect of a real revolution, not proof that the underlying technology is fake. The two phenomena come together as a pair.

Gurley posits that a bubble isn't a sign that a technology is fake. Citing economist Carlotta Perez, he argues that if a tech wave is real and generates wealth quickly, it will inevitably attract speculators and charlatans, making a bubble an expected consequence of its success.

Howard Marks distinguishes between two bubble types. "Mean reversion" bubbles (e.g., subprime mortgages) create no lasting value. In contrast, "inflection bubbles" (e.g., railroads, internet, AI) fund the necessary, often money-losing, infrastructure that accelerates technological progress for society, even as they destroy investor wealth.

The most significant market bubbles, like railroads, the internet, and AI, are driven by genuinely transformative ideas. Their obvious, world-changing potential attracts massive investment, which inevitably gets overdone, leading to a bubble and subsequent crash, even for successful underlying technologies like Amazon.