According to a recent regulatory filing, the activist investor Carl Icahn has increased his ownership of the natural and organic products company The Hain Celestial Group. TheStreet.com reports that Icahn—who has been called “the shrewdest investor on the planet”—now owns 6.537 million shares, or nearly 15% of the Melville, New York-based company.

Icahn, who was already the largest Hain Celestial shareholder, increased his stake in the company by about 30% since September, when it was last reported that Icahn owned 5.04 million shares. In July, Hain Celestial agreed to add Icahn’s son and Icahn Capital Managing Director David S. Schechter to its board in return for Icahn supporting the company’s current directors. Under the terms of the deal, Icahn can acquire up to 20 percent of Hain Celestial’s total outstanding shares.