Historically, Trump's statements on reducing drug prices have led to volatility in the pharmaceutical sector. This executive order may lead to decreased revenue for pharmaceutical companies, potentially negatively impacting their stock prices. The order's focus on delivering 'most-favored-nation' pricing to American patients could lead to a decrease in profit margins for these companies, causing a bearish market sentiment. Regulatory implications and potential changes to the pharmaceutical industry's business model may also contribute to market uncertainty. As a result, investors may exercise caution when investing in pharmaceutical stocks, at least in the short term, until the full implications of the executive order are understood.