An investment approach that places securities into groups based on the correlation found among their returns. Securities with high positive correlations are grouped together and segregated from those with negative correlation. Between each cluster, very little correlation should exist. Holding stocks in each cluster provides the investor with a diversified portfolio. Taobiz explains Cluster Analysis Cluster analysis enables the investor to eliminate any overlap in his or her portfolio by identifying securities with related returns. This approach increases diversification, which provides the investor will a less risky portfolio. Cluster analysis has uncovered certain categories of stocks, such as cyclical and growth stocks.