CFA Institute CFA-Level-II Exam - Topic 3 Question 113 Discussion

Tamara Ogle, CFA, and Isaac Segovia, CAIA, are portfolio managers for Luca's Investment Management (Luca's). Ogle and Segovia both manage large institutional investment portfolios for Luca's and are researching portfolio optimization strategies.

Ogle and Segovia begin by researching the merits of active versus passive portfolio management. Ogle advocates a passive approach, pointing out that on a risk-adjusted basis, most managers cannot beat a passive index strategy. Segovia points out that there will always be a need for active portfolio managers because as prices deviate from fair value, active managers will bring prices back into equilibrium. They determine that Treynor-Black models permit active management within the context of normally efficient markets.

Ogle decides to implement Treynor-Black models in her practice and starts the implementation process. In conversations with her largest client's risk manager, Jim King, FRM, she is asked about separation theorem in relation to active portfolio management. She responds that separation theorem more properly relates to asset prices deviating from and gravitating toward their theoretical fair price. King next asks Ogle about the differences between the Sharpe ratio and the information ratio and the difference between the security market line (SML) and the capital market line (CML).

After reallocating her client portfolios based on using the Treynor-Black model, Ogle discusses the results with Segovia. Ogle states that she is satisfied with the current methodology, but given her preference for passive management, she is still concerned about relying on analyst's forecasts. Segovia tells Ogle that he will research methods for modifying the Treynor-Black model to account for analyst forecasts.

The optimal portfolio for an investor under the Treynor-Black model: