Pharmaceutical stocks experienced a sharp decline following the announcement of a new regulatory or legislative development perceived as unfavorable to the industry. The move is expected to adversely impact major pharmaceutical companies as well as Pharmaceutical Benefit Management (PBM) firms, including CVS, Cigna, Humana, and Express Scripts. Market participants anticipate a challenging environment for biotech and pharmaceutical sectors, with expectations of continued downward pressure on stock prices. The sentiment reflects concerns over the potential legal approval of measures that could disrupt the current pharmaceutical business model.