Historical Example
In the 1990s, many investors compared their portfolio performance to the S&P 500 index, which experienced significant growth. This led to a widespread belief that any investment strategy should be able to outperform the S&P 500. However, this benchmark was not appropriate for all types of portfolios, as it only represented a specific segment of the market and did not account for the risk associated with different investment strategies.
Real-World Example
An investor has a portfolio of 60% stocks and 40% bonds. To evaluate the performance of their portfolio, they can use a blended benchmark, such as a combination of a large-cap equity index (for the stock portion) and an aggregate fixed-income index (for the bond portion). By comparing their portfolio's performance to this blended benchmark, the investor can determine if their investment strategy is effective or if adjustments need to be made.