控股股东樊培仁被留置并立案，扬帆新材低开8.97%

Group 1 - The core point of the article is that Yangfan New Materials (300637) experienced a significant drop in stock price, opening at 14.61 CNY per share, down 8.97% [1] - The company disclosed that its controlling shareholder and actual controller, Fan Peiren, has been placed under investigation by the Lishui City Supervisory Committee in Zhejiang Province [1] - The investigation includes a "Notice of Case Filing" and a "Notice of Detention" issued to Fan Peiren, indicating serious legal issues for the company [1]