The healthcare sector experienced a significant downturn after HCA Healthcare, a major hospital operator, lowered its full-year 2026 earnings guidance. The revision was attributed to an unfavorable shift in payer mix, with an increase in uninsured patients who have lost coverage through health insurance exchanges. This news has not only impacted HCA's stock but has also led to declines in the shares of other hospital operators, signaling sector-wide concerns about profitability. The broader market is also facing headwinds from rising geopolitical tensions.