If bonds can earn you nearly as much as stocks, but at a reduced risk, then the case for owning equities becomes less compelling. With bond yields climbing when stocks were already getting pricey, a key measure known as the equity risk premium is sounding alarm bells for some. Over the past week, this gauge—measured by the difference between the S&P 500's earnings yield and the yield on 10-year Treasurys—touched the lowest level in more than 20 years, notes markets writer Gunjan Banerji. The realization that higher rates aren't going away soon is also spurring businesses to move ahead with deals, despite the higher debt costs associated, says columnist Telis Demos.