John Smith is a portfolio manager at XYZ Investments, overseeing a diversified equity fund. Over the past year, the fund has generated a return of 12%, outperforming the benchmark index, which returned 8%. This fund exhibits a standard deviation of returns of 15%, while the benchmark has a standard deviation of 10%.

Using the information provided, calculate the fund's Sharpe ratio and Jensen's alpha.

Discuss the implications of these performance metrics in the context of risk-adjusted performance evaluation and how they can guide future investment strategies.