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.
Generative AI models are trained on existing human-generated text, causing them to reflect and amplify mainstream thought. When prompted on contrarian topics, they will either omit them or frame them as fringe ideas. AI is a tool for understanding the consensus view, not for generating truly original, non-consensus insights.
During a severe, protracted downturn like the Great Depression, traditional low-multiple 'value' stocks often go bankrupt. In contrast, horrendously expensive but high-quality companies like Coca-Cola survive the economic turmoil. In a true crisis, survivability and quality trump a low valuation.
Historical data shows no exceptions to the rule that an asset class reaching a two-standard-deviation (two sigma) valuation above its long-term trend will eventually return to that trend. This statistical certainty applies to stocks, bonds, commodities, and currencies, making severe drawdowns from such peaks inevitable.
Jeremy Grantham's value-oriented discipline stems from a deeply ingrained sense of frugality forged during his WWII-era childhood. This non-negotiable aversion to 'wasting money' is not an intellectual exercise but a core part of his character, making it easier to resist market manias and focus on price.
GMO's spectacular early success came from investing in obscure small-cap value stocks that no institutional investors followed. This created an 'unfair advantage' where they could get deep insights directly from management and competed only against amateur local shareholders, a battle they could easily win.
The 2022 bear market was on track to be a typical crushing of a super bubble. However, the sudden, tangible emergence of AI provided a powerful new investment theme that changed animal spirits and halted the market's full reversion to its mean. This interruption of a bubble's collapse by a new bubble is a unique historical event.
Large investment firms like Goldman Sachs or JP Morgan will not publicly call a market top, even if their internal analysts believe it's severely overpriced. Their public commentary is a form of risk management to avoid losing clients during a euphoric bull market, creating a dichotomy between internal analysis and external propaganda.
After the dot-com bubble burst, Jeremy Grantham's GMO was vindicated. However, the clients who had fired them for underperforming during the mania did not return. The firm attracted new clients who appreciated their discipline, but the original relationships were permanently severed by the pain of relative underperformance.
A key indicator of a bubble's final stage, observed only four times in U.S. history (1929, 1972, 2000, 2021), is when speculative, high-beta stocks that led the rally start to fall sharply while blue-chip indices continue to grind higher. This market divergence is a 'primal scream' that a crash is imminent.