Two insiders just filed a $219.6M open-market buy, and the number alone tells you less than you'd think

Form 4 filings this week: two insiders at Madison Air Solutions (MAIR) disclosed open-market purchases totaling $219.6M. Same week, smaller filings came in from insiders at ACDC ($5.7M), DKS ($3.8M) and INBX ($3.5M).

The instinct is to treat the $219.6M as the strongest signal on the list because it's the biggest number. It isn't necessarily. Dollar size scales with how wealthy the filer already is, so a $200K purchase from a director whose whole stake is $700K can be a bigger statement than $200M from someone sitting on $2B. Without knowing the filer's existing position, the raw dollar figure alone doesn't tell you much.

What does matter regardless of size: code P specifically (open-market purchase with the insider's own cash, not a grant or option exercise), and clusters (multiple insiders buying in the same window, which this MAIR filing is).

Figures as filed through Sep 17, 2026. Source: SEC EDGAR full-text search, form type 4, transaction code P.