Thomas Frist Jr. does not seem to have lost faith in the company he co-founded in 1968.

The HCA Healthcare co-founder, who served as chairman and CEO before retiring, bought on Monday nearly 90,000 shares in the company, growing his direct holdings by more than 22 percent, according to regulatory filings. He purchased the shares for a range of average prices between $209.73 per share and $215.29 per share.

HCA’s stock traded north of $270 per share in April but plummeted after its first quarter earnings report showed that the company was still struggling with paying workers, especially contract nurses.

Since Frist bought the shares, the price has increased slightly. Before trading began Wednesday, the price had reached $224.80, meaning Frist booked more than $1 million in profit on the single-day activity.