The Relationship Between Interest Rates and Stock Market Valuation

Barron’s (July 23, 2021) published my Letter to the Editor:

Exception to the Rule

To the Editor:
The suggestion that stocks are overvalued based on the “Rule of 20,” which posits that the sum of inflation and the stock market’s price/earnings ratio should add up to 20, and is based on data going back to 1957, omits an examination of interest rates (“By This Key Measure, the Stock Market Is Trading at Dot-Com-Era Levels,” Up & Down Wall Street, July 16). The 10-year U.S. Treasury rate averaged 5.75% from 1957 through 2021, and 6.65% through 2007, prior to the Great Recession. However, it currently equals only 1.31%, its lowest level over this 65-year time period. Since interest rates are to asset prices what gravity is to matter, the Rule of 20 cannot be applied to determine if current stock market valuations are excessive.