Over the past 20 years, the S&P 500 has generated an average annual return of around 7-8%, but specific figures may vary. While past performance does not guarantee future results, some investors speculate whether the next 20 years will mirror this trend. High-yield stock portfolios have shown the potential to outperform the S&P 500, as evidenced by a +34.37% annual return for a particular portfolio, beating the S&P 500's Div.-Growth +21.20%.