GMO is a Boston asset manager co-founded in 1977 by Jeremy Grantham with Richard Mayo and Eyk Van Otterloo, known for valuation-driven dynamic asset allocation built on long-horizon mean reversion. Grantham is famous for calling historic bubbles, warning publicly ahead of both the 2000 dot-com crash and the 2008 financial crisis. Flagship publications include the GMO Quarterly Letter (now written by Asset Allocation co-heads Ben Inker and John Pease), Grantham's Viewpoints essays and the 7-Year Asset Class Forecast.
This report warns that today's high corporate profits and stock prices are unlikely to last forever. History shows that extreme levels tend to return to normal over time. For regular investors, this means don't assume the good times will keep going—be ready for a slow, multi-year adjustment. It's worth reading because it challenges the popular idea that 'this time is different,' helping you avoid overpaying for stocks.
GMO research report points out that current market behavior suggests investors view high profit levels as permanent, but historically, a conventional bear market of 15% to 20% could occur at any time due to various reasons. The core argument is that the market may face a more persistent reversion tr
This chapter examines whether the market’s assumption of “permanently” high profitability is valid. The author points out that current market pricing implies an expectation that high corporate profit margins will persist indefinitely, but historically, such assumptions have often been overturned by mean reversion. Meanwhile, conventional 15%-20% bear markets can occur at any time for various reasons, but this chapter focuses on a more fundamental structural reversion—namely, the return of earnings, interest rates, and pricing trends to pre-1997 levels.
The author’s central judgment is that the market mistakenly views current high profitability as a permanent state, whereas these indicators will actually undergo a long-term reversion trend. This process may take far longer than any value-oriented fund manager expects, meaning investors should be wary not of short-term volatility but of a structural adjustment lasting several years. The counterintuitive point is that while market consensus sees high profitability as the “new normal,” the author argues this is precisely the greatest source of risk.
| Indicator | Pre-1997 Trend | Current Level | Direction of Reversion |
|---|---|---|---|
| Corporate Profit Margin | Long-term average ~5-6% | Approaching 10% | Downward |
| Real Interest Rate | ~2-3% | Near 0% or negative | Upward |
| Stock Valuation (CAPE) | ~15-20x | Above 30x | Downward |
This chapter does not specifically mention individual stocks or companies; it primarily discusses macro market indicators (e.g., profit margins, interest rates, valuation multiples). Implicit asset classes include: