Filings for Dec 8, 2021 show insider purchases at 40 companies, adding up to roughly $228.8 million. The biggest was TWTR (TWITTER, INC.), where Silver Lake Group, L.L.C. led about $93.5 million of buying.
Cluster buying (3+ insiders) is running at 153 companies this month. CEOs and CFOs show up 11 times in today's list. One buy doesn't make a thesis, but it's a good place to start digging.