These ten healthcare stocks posted the biggest one-month losses

As the month of September 2026 comes to a close, the broader stock market has exhibited a mix of late-summer consolidation and selective sector rotation.

Investors continue to digest shifting macroeconomic data and adjust their portfolios for the final stretch of the third quarter, creating a dynamic backdrop where individual stock picking and sector trends take center stage. Within this environment, several pocket-level opportunities have emerged, particularly in healthcare-related assets.

Below is a list of the worst performing healthcare stocks over the past one month. The list is ranked based on lowest one month price performance, with all stocks currently holding a Hold Quant Rating from Seeking Alpha's Quant Ratings system.

The list is topped by Liquidia Corporation (LQDA), with a one month price performance of -55.30%. Dyne Therapeutics, Inc. (DYN) and Structure Therapeutics Inc. (GPCR) are next, with Acadia Pharmaceuticals Inc. (ACAD) and Ionis Pharmaceuticals, Inc. (IONS) rounding out the rest of the top five.

The bottom performers span the pharmaceuticals and biotechnology industries, with The Cooper Companies, Inc. (COO) representing health care supplies as the lone diversified name on the list.

Here is the list:

1. Liquidia Corporation (LQDA), 1 month performance percentage: -55.30%

2. Dyne Therapeutics, Inc. (DYN), 1 month performance percentage: -35.74%

3. Structure Therapeutics Inc. (GPCR), 1 month performance percentage: -33.99%

4. Acadia Pharmaceuticals Inc. (ACAD), 1 month performance percentage: -30.78%

5. Ionis Pharmaceuticals, Inc. (IONS), 1 month performance percentage: -26.86%

6. Arrowhead Pharmaceuticals, Inc. (ARWR), 1 month performance percentage: -22.92%

7. Immunome, Inc. (IMNM), 1 month performance percentage: -21.98%

8. Enliven Therapeutics, Inc. (ELVN), 1 month performance percentage: -20.77%

9. The Cooper Companies, Inc. (COO), 1 month performance percentage: -20.57%

10. Erasca, Inc. (ERAS), 1 month performance percentage: -18.69%

Health Care ETFs: (XLV), (VHT), (IHI), (IXJ), (IYH), (FHLC), and (FXH)