The 1960s gave birth to the Go-Go Years on Wall Street, a significant cultural shift that coincided with the early success of William J. O’Neil, an outstanding young trader at securities firm Hayden, Stone & Co. who had developed his own signature style of stock analysis. While many investors were relying on P/E ratio as a key stock screening metric, O’Neil studied historical models of winning stocks and developed a proprietary trading methodology that blends quantitative and qualitative analysis—the method we still use today.