PT - JOURNAL ARTICLE AU - Ronald J. Surz AU - Mitchell Price TI - The Truth About Diversification by the Numbers AID - 10.3905/joi.2000.319444 DP - 2000 Nov 30 TA - The Journal of Investing PG - 93--95 VI - 9 IP - 4 4099 - https://pm-research.com/content/9/4/93.short 4100 - https://pm-research.com/content/9/4/93.full AB - Most of us have heard the statement “90% of available diversification is achieved with a 15-stock portfolio.” Very few, if any, of us behave as though we believe this statement, and there's good reason why—it's not true. This article lays out the truth about how many times it takes to obtain adequate diversification in a domestic equity portfolio. It's much more than 15.