Shares of Eli Lilly were taking a 6.9% hit toward a two-month low in recent trading, enough to make them the S&P 500's biggest decliner. The problem is that the drug giant provided fourth-quarter revenue guidance that was below Wall Street expectations,

Incretins such as glucagon-like peptide-1, or GLP-1, are used in diabetes and obesity drugs like Eli Lilly’s Mounjaro and Zepbound. The stock dropped 8.2% in morning trading, enough to make it the S&P 500 index’s worst performer. It was also on track ...