(Bloomberg) -- The billionaire chairman of Continental Resources Inc. bought almost $10 million of the oil producer’s stock just before this week’s price slump.

Harold Hamm bought 270,000 shares of the company he founded in 1967 earlier this week, when prices were at their highest since 2019, according to data compiled by Bloomberg. Those were his first Continental purchases since September. On Thursday, the stock plunged 6.3% as a sell-off in energy markets dragged shale drillers lower.

Continental’s shares have plunged by more than 50% from a 2014 peak as lower oil prices pummeled the shale industry after years of runaway spending and overproduction. While the company’s market value has more than doubled over the past year amid a broader industry rebound, analysts currently see limited upside for the stock.

Continental rose 1.5% to $34.78 a share as of 11:41 a.m. in New York. A spokesperson for the company didn’t immediately respond to a request for comment.

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