Jeremy Grantham

Jeremy Grantham is the investor who has spent decades studying patterns of market exuberance and collapse, consistently sounding alarms at the very moments when other investors are euphoric. His repeated accuracy stands as a powerful rebuttal to the uncritical faith in market efficiency.

Born in October 1938 in Britain, Grantham studied economics at the University of Sheffield and then earned an MBA from Harvard Business School before settling in the United States. In 1977 he co-founded GMO (Grantham, Mayo, Van Otterloo) in Boston. By March 2015 assets under management exceeded $118 billion, making GMO one of America's leading asset managers, though assets have since contracted to roughly $65 billion.

Grantham's place in investment history was secured by his record of calling major bubbles. Before the 2000 dot-com crash he publicly flagged the overvaluation of technology stocks. At a time when the Nasdaq was surging, warning of a bubble carried substantial business risk, and GMO did indeed suffer client outflows. Yet the post-2000 collapse vindicated his analysis. He sounded similarly prescient warnings about the housing bubble ahead of the 2007-2008 financial crisis, and this string of successful calls cemented his reputation as a 'bubble-prediction guru.'

The hallmark of Grantham's bubble analysis is its grounding in the statistical theory of mean reversion. He has repeatedly demonstrated, with historical data, the regularity with which asset prices that deviate significantly from long-term averages eventually revert. This analytical framework provides an intellectual tool for calmly identifying overvaluation and undervaluation without being swayed by the emotionally and narratively driven short-term movements of markets.

Notably, Grantham also launched one of the very earliest index funds in the early 1970s, roughly contemporaneous with John Bogle's founding of Vanguard in 1975. That he saw the potential of passive investing at such an early stage — while simultaneously being an active manager renowned for predicting bubbles — speaks to his intellectual flexibility.

On the policy front, Grantham has been a vocal critic of post-2008 monetary easing, arguing that excessive reliance on loose policy breeds new asset bubbles. Bloomberg Markets named him one of the '50 Most Influential People' in 2011. In recent years he has turned his attention to environmental issues, making large-scale donations to climate-change initiatives through the Grantham Foundation for the Protection of the Environment — a theme that connects naturally with his long-term market analysis and resource-constraint concerns.

GMO's quarterly letters, alongside Buffett's shareholder letters, are among the most closely followed periodic publications in the investment community. Grantham's data-driven, historically grounded analysis serves as a tool for visualizing market overheating and has influenced the asset-allocation decisions of many institutional investors.

Grantham's role is that of the 'inconvenient-truth teller' of the investment world. The combination of courage to articulate unpopular views in the short term and the calm analytical power grounded in long-term data has filled a rare and indispensable role in a financial market dominated by crowd psychology.