THE TREYNOR CAPITAL ASSET PRICING MODEL

Craig W. French

History generally accords the development of the single-period, discrete-time Capital Asset Pricing Model (CAPM) to the works of Sharpe (1964), Lintner (1965a,b) and Mossin (1966).We explore the early work of another notable financial economist, Jack L. Treynor, who also deserves credit for the original Capital Asset Pricing Model because of his revolutionary manuscripts—“Market Value, Time, and Risk”, Treynor (1961), and “Toward a Theory of Market Value of Risky Assets”, Treynor (1962)—which were circulated during the 1960s in mimeographed draft form but have never been published in an academic or practitioner journal. Mr. Treynor’s early work appears to have predated and anticipated Sharpe (1964), Lintner (1965a,b) and Mossin (1966). However, while financial economists initially credited Mr. Treynor for his innovation, the Treynor CAPM has not enjoyed a broad public reach. This, apparently, is the reason Mr. Treynor is not consistently recognized as one of the primary architects of the CAPM.