It's not secret knowledge at all. Just invested 2 minutes in searching:

> US health insurers report billions in first quarter as small providers face stress

> UnitedHealth Group, reported $4.9bn in profits in the first quarter of 2021 while CVS Health reported $2.2bn

- https://www.theguardian.com/business/2021/may/08/us-health-i...

> Major U.S. Health Insurers Report Big Profits, Benefiting From the Pandemic

- https://www.nytimes.com/2020/08/05/health/covid-insurance-pr...

> The health insurance industry continued its tremendous growth trend as it experienced a significant increase in net earnings to $31 billion and an increase in the profit margin to 3.8% in 2020 compared to net earnings of $22 billion and a profit margin of 3% in 2019.

- https://content.naic.org/sites/default/files/inline-files/20...