IBD founder William J. O’Neil made industry-level study a central focus based on early company research that showed more than 35% of the strength of a winning stock’s advance owed to the strength of its industry group at the time of its breakout. Another 10% to 15% of that same stock’s strength was linked to the strength of the overall sector. The combination meant as much as 50% of a stock’s strength is tied to industry group and sector attributes at the time of its breakout.