Insider buyers were busy on May 13, 2021: 40 companies, $17.6 million in open-market purchases all told. The biggest was CAR (AVIS BUDGET GROUP, INC.), where Hees Bernardo led about $5 million of buying.
Cluster buying (3+ insiders) is running at 63 companies this month. Six of the buys came from a CEO or CFO. One buy doesn't make a thesis, but it's a good place to start digging.