Insider buyers were busy on Sep 21, 2021: 31 companies, $138.8 million in open-market purchases all told. At the top: ALPN, $48 million bought, with Decheng Capital Management III (Cayman), LLC as the largest buyer.
Cluster buying (3+ insiders) is running at 95 companies this month. C-suite buying: four companies. As always, a purchase is a data point, not a recommendation.