sentences:  The speech and article challenged the idea that equity markets are efficient through a study of nine successful investment funds generating long-term returns above the market index.All these funds were managed by Benjamin Graham's alumni, following the same "Graham-and-Doddsville" value investing strategy but each investing in different assets and stocks.Columbia Business School arranged celebration of Graham–Dodd's jubilee as a contest between Michael Jensen, a University of Rochester professor and a proponent of the efficient-market hypothesis, and Buffett, who was known to oppose it.