Abstract: An investment services architecture provides a suite of investment management tools and services to investors. The architecture includes an investment services hosting site that offers investment services to investors who access the services via the Internet using various investor computing devices. The architecture provides for the identification of a set of investment holdings associated with a first investment portfolio and identification of a set of investment holdings associated with a second investment portfolio. A ideal investment portfolio is created by merging the set of investment holdings associated with the first investment portfolio and the set of investment holdings associated with the second investment portfolio. Using the ideal investment portfolio, the architecture is able to suggest sales and purchases of holdings in an effort to achieve investment performance similar to the ideal investment portfolio.