Insider trading, explained
The data on this site is only useful if you know how to read it. These guides cover what Form 4 actually reports, which transaction codes represent real buying, and where the numbers routinely mislead people.
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What Is SEC Form 4? A Plain-English Guide to Insider Trading Filings
Form 4 is how corporate insiders report trades in their own company's stock. Here is what it contains, who has to file one, how fast, and how to read it without being misled.
Is Insider Buying a Bullish Signal? What the Evidence Actually Says
Insider purchases have historically modestly outperformed, and insider sales have almost no predictive value. Here is what the research found, why the effect exists, and the ways the data misleads people.
Form 4 Basics
What insiders have to report, and how to read it.
- What Is SEC Form 4? A Plain-English Guide to Insider Trading FilingsAugust 11, 2026 · 5 min read
Form 4 is how corporate insiders report trades in their own company's stock. Here is what it contains, who has to file one, how fast, and how to read it without being misled.
- Form 4 Transaction Codes Explained: What P, S, A, M and F Actually MeanAugust 11, 2026 · 4 min read
Every SEC Form 4 transaction code, in plain English — which ones represent real buying and selling, and which are compensation events dressed up as trades.
Reading the Signal
What insider trading data does and does not tell you.
Rules & Filings
Trading plans, deadlines, amendments and the mechanics of disclosure.