On October 9, Alignment Healthcare, Inc. fell 20.46% in regular trading, trading at $6.38/share, with turnover of $21.108 million.

The core catalyst was the company's disclosure that its California HMO plan — covering roughly 75% of membership — is expected to see its 2027 CMS star rating drop from 4.0 to 3.5 stars, driven by higher industry thresholds and weaker results on certain triple-weighted health outcomes and Part D measures. Alignment Healthcare plans to appeal certain CMS calculations and pursue litigation challenges, but the near-term uncertainty surrounding quality bonus payments and membership growth has prompted a sharp repricing of risk. William Blair downgraded the stock to Market Perform from Outperform.

Within the Managed Health Care sector, Humana rose 14.54%, UnitedHealth rose 1.34%, Clover Health Corp rose 9.17%, Elevance Health rose 0.2%, and HealthEquity fell 0.05%.

Alignment Healthcare, Inc. operates a tech-enabled Medicare Advantage platform providing customized healthcare to seniors across California, North Carolina, Nevada, Arizona, Florida, and Texas.