Why insider buys carry more information than insider sales

Scroll any day's Form 4 feed and sales dominate. Compensation vests, options get exercised, tax shares get withheld, and 10b5-1 plans print on a calendar. None of that requires the insider to think the stock is expensive today.

Open-market purchases with cash (code P) are the exception. There is essentially one economic reason to write a personal check for more shares: the buyer expects them to be worth more than the price paid. That does not make the buy a recommendation. It makes it a better research cue than a routine sale.

A sale can still be worth opening - clustered C-suite selling, unusual size versus the person's history, or a discretionary sale with no plan. The default, though, is noise until the footnotes say otherwise.

The Form 4 Greediness Score is a 0 to 100 reading of structural conviction: role, cluster activity, size versus history, position impact, filing urgency, and direct ownership. Those factors can light up on a sale as easily as on a buy. A Strong-band sale means the filing is structurally notable, not that we think the insider is bearish.

In practice, start with Strong-band open-market buys. Use sales as a second pass: confirm codes, the 10b5-1 box, and whether the holding is direct. For a worked buy example see the Jefferies CEO and CFO case study. For a worked sale cluster see the Sea Limited C-suite filings.

It does not prove that buys predict returns, that sales predict declines, or that copying either side is a strategy. Academic findings on purchase information are about average historical associations in Form 4 data, not about any one ticker. Open the live feed at /app?band=strong, verify the primary Form 4, and keep valuation and fundamentals in the research process.