Pharmaron's stock plummeted 5.10% intraday, weighed down by planned share sales from major shareholders and broad declines across the life sciences sector.

The decline follows recent disclosures that shareholders Xinzhong Kangcheng and its concert party Xinzhong Longcheng plan to reduce holdings by up to 27.56 million shares, representing approximately 1.50% of total share capital, within three months starting May 27. Additionally, Longtai Zhongxin, a concert party of co-founder Zheng Bei, plans to sell up to 1.33 million shares. The combined planned reduction totals about 1.57% of outstanding shares, creating an overhang on the stock.

The selling pressure coincides with weakness across the life sciences tools and services sector, with peers including Wuxi Biologics, Wuxi AppTec, Wuxi XDC, and Insilico also trading lower during the session.