The article investigates why the risk of investing in US stocks and bonds changes over time. It looks at how economic news affects the risk of these investments and whether this leads to changes in the expected returns. The researchers found that stock prices are more affected by changes in their own risk, especially after Producer Price Index (PPI) announcements. On the other hand, bond prices are more influenced by changes in the risk related to economic events. Employment reports and PPI releases are key factors that impact the risk of investing in stocks, notes, and bonds.