A key metric derived from the bond market is signaling that U.S. stocks are currently undervalued, according to The Wall Street Journal. This indicator, which compares the earnings yield of the S&P 500 to the yield on the 10-year Treasury note, has historically suggested attractive entry points for equity investors.

When the earnings yield of the S&P 500 exceeds the 10-year Treasury yield by a significant margin, it implies that stocks are offering a higher potential return relative to safer government debt. This relationship is often viewed as a gauge of relative attractiveness between asset classes.

However, the Journal cautions against blindly heeding this signal. Several factors can influence this comparison, and a "cheap" stock valuation doesn't always translate into immediate gains. Market sentiment, economic outlook, and company-specific news all play crucial roles in stock performance. Investors are advised to consider a broader range of factors beyond this single bond market metric when making investment decisions.