Joe Granville

Joe Granville worked for E.F. Hutton and published the Granville Market Letter for over 50 years. He became famous — and occasionally infamous — as one of the most theatrical and confident market forecasters of the 20th century, known for performances at investment conferences involving props, theatrical costumes, and a marching band. Granville invented On-Balance Volume (OBV), a technical indicator that adds volume on up-days and subtracts volume on down-days to create a running cumulative line. The indicator is used to confirm price trends — if OBV is rising while prices are rising, the trend is confirmed; if OBV diverges from price, a reversal may be forthcoming. OBV remains one of the most widely used volume indicators in technical analysis. Granville achieved a remarkable demonstration of market-moving power in January 1981: he sent a telephone message to his subscribers recommending selling all stock immediately and going short. The news spread so rapidly that the Dow Jones Industrial Average fell approximately 2.4% in a single session — a significant and largely unprecedented response to an individual analyst's recommendation. His subsequent calls proved less accurate, and his influence faded, but OBV remains his lasting contribution to technical analysis. He passed away in 2013.