Fama's actual position was of course more nuanced than simply declaring that "markets are efficient". His key EMH paper [1] notes that a generic formulation of

Fama's actual position was of course more nuanced than simply declaring that "markets are efficient". His key EMH paper [1] notes that a generic formulation of the EMH, that security prices at any time "fully reflect" all available information is untestable: you need narrow down the information set and the pathways in which they are reflected in prices. The paper goes over various technical definitions of "efficiency" and concludes from reviewing the empirical literature (in 1970) that no evidence against certain formulations (weak, semi-strong) of the EMH has been found/published. I don't think it's fair to characterize Fama as "chief cheerleader" of the EMH, but the papers are there for the readers to judge for themselves. [1] https://www.jstor.org/stable/2325486 https://www.jstor.org/stable/2325486, http://efinance.org.cn/cn/fm/Efficient%20Capital%20Markets%20A%20Review%20of%20Theory%20and%20Empirical%20Work.pdf http://efinance.org.cn/cn/fm/Efficient%20Capital%20Markets%2...