What rate of return on a security to the expected rate of return on a portfolio?

The rate of return on a security is typically compared to the expected rate of return on a portfolio to assess its contribution to overall portfolio performance. If the security's rate of return exceeds the portfolio's expected rate, it may be considered a good investment; conversely, if it falls short, it might detract from overall returns. Investors often use metrics like the Sharpe ratio to evaluate the risk-adjusted return of individual securities relative to the portfolio. This comparison helps in making informed investment decisions and optimizing asset allocation.