Pharmaceutical shares just witnessed their strongest week in 23 years, thanks to Pfizer's (PFE) major drug-pricing and tariff deal with the U.S. government that helped ease long-standing pressures on the industry, per a Bloomberg article, as quoted on Yahoo Finance.The S&P 500 Pharmaceuticals Index jumped 10.8% last week, marking its strongest performance since July 2002. With these gains, the index is now up only 6.6% for the year, still underperforming the S&P 500, which is up 14.4% (as of Oct. 3, 2025).P ...