Insider clusters that have earned the right to be watched

Two or more insiders buying within a 7-day window. Cluster score weighs role mix, 10b5-1 plan ratio (Jagolinzer 2009), and routine-vs-opportunistic patterns (Cohen-Malloy-Pomorski 2012). Anchor: Kang-Kim-Wang 2024 — +3.8% abnormal return over 21 trading days on cluster purchases vs +2.0% non-cluster, 457k purchases 1986-2016.