William O'Neil's CANSLIM — The Complete Growth Stock Selection System

CANSLIM is not a checklist of seven independent criteria. It is a complete philosophy of growth stock selection, built from O'Neil's analysis of every major winning stock in the US market from 1953 to 2009. Every letter captures a characteristic that appeared consistently in the greatest growth stocks before their major advances — and whose absence consistently identified stocks that failed.

Why This Matters

William O'Neil founded Investor's Business Daily in 1984 after spending two decades studying the specific characteristics of market-leading growth stocks at the moment before their major price advances. His methodology, CANSLIM, was the product of empirical research rather than theory. He studied what winning stocks had in common before they won — not what they looked like after they had already risen. The result is a system that blends fundamental quality criteria (earnings, new products, institutional ownership) with technical market evidence (supply/demand, market direction) to identify high-probability growth opportunities before they are universally recognised. For the growth investor who thinks fundamentally but wants objective confirmation that the market is agreeing, CANSLIM provides a systematic bridge between qualitative conviction and market evidence.