The article discusses the history of the equity risk premium, which is the extra return investors expect from stocks compared to risk-free investments. Researchers have looked at long-term data to estimate this premium and how historical events may affect it. The equity risk premium is crucial for predicting portfolio growth, determining project costs, and setting stock return expectations. Surprisingly, calculating this premium is a relatively recent practice, with reliable data only available since the mid-20th century. The Capital Asset Pricing Model (CAPM) played a key role in developing precise estimates of the equity premium.