A guest offers a more precise alternative to the cliché that history rhymes: Voltaire's observation that "history never repeats itself, man always does." This insight pinpoints human nature—greed, fear, and FOMO—as the constant driver of speculative manias, even as the specific assets and technologies change.

A true market bubble isn't defined by high valuations but by collective psychology. The most dangerous bubbles form when skepticism disappears and everyone believes prices will rise indefinitely. Constant debate about a bubble indicates the market hasn't reached that state of universal conviction.

A key behavioral indicator of an overheated market is when investors justify buying stocks with indirect, "bank shot" reasoning, like pitching airlines as a play on weight-loss drugs reducing fuel costs. This stretched narrative suggests prices are detaching from fundamentals.

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.

Widespread public debate about whether a market is in a bubble is evidence that it is not. A true financial bubble requires capitulation, where nearly everyone believes the high valuations are justified and the skepticism disappears. As long as there are many vocal doubters, the market has not reached the euphoric peak that precedes a crash.

Investors are piling into equities not because they are bullish on corporate profits, but because traditional safe havens have become unreliable. This "There Is No Alternative" (TINA) scenario, where buying is driven by a lack of options rather than fundamentals, is a classic precondition for an asset bubble and potential crash.

Financial history rhymes because the underlying driver—human nature—is constant. Core desires for wealth, recognition, and love, along with the fear of pain and envy of others' success, have remained unchanged for millennia. These emotions will continue to fuel bubbles and crashes, regardless of new technologies or financial instruments.

Historical bubbles, like the dot-com era, occur only when everyone capitulates and believes prices can only go up. According to Ben Horowitz, the constant debate and anxiety about a potential AI bubble is paradoxically the strongest evidence that the market has not yet reached the required state of collective delusion.

Contrary to intuition, widespread fear and discussion of a market bubble often precede a final, insane surge upward. The real crash tends to happen later, when the consensus shifts to believing in a 'new economic model.' This highlights a key psychological dynamic of market cycles where peak anxiety doesn't signal an immediate top.