CStone Pharmaceuticals (HKG:2616) said CEO, President of R&D and executive director Jianxin Yang bought 496,000 shares in the open market for more than HK$2.7 million from Sept. 17 to 22, according to a Thursday Hong Kong bourse filing.

Following the purchases, Yang's interest in CStone rose to about 5.31% of the company's issued share capital. He has bought a total of 14.21 million shares in the open market since becoming CEO in August 2022.