Wall Street has slashed its estimates for corporate profits in the final months of 2023. Yet investors appear to be taking the shifting picture in stride, partly because much of the blame appears to fall on just two companies: Pfizer and Merck. 

Analysts cut their projections for fourth-quarter earnings at companies in the S&P 500 by 3.9% in October, according to FactSet, more than twice the 10-year average of 1.8%. That marks the deepest reduction during the first month of a quarter in more than three years.