Insider trading, explained

Insiders report within two business days. That is not the same as you seeing it within two days. Step through the whole timeline, from the trade to a readable row.

All twenty Form 4 transaction codes, how often each appears, and whether it represents a real decision to trade. Searchable and sortable.

A Form 4 is a small form with a few fields that decide everything. Click through an annotated one and learn which box to read first — and which ones mislead.

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.

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.

The same four tests this site uses to flag an open-market purchase as notable — first buy, size against the insider's own history, price, and change in their stake. Put in the numbers, get the read.

Six real-world insider-trading scenarios. Decide how much each one tells you, then see the reasoning. Most people over-rate the acquisitions that aren't purchases.

One insider buying can be idiosyncratic. Several, independently, in a short window is one of the strongest patterns in insider-trading data. Here is the definition, with a toy you can play with.

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.

Most large insider selling fires from a plan set up months earlier and means almost nothing. Walk this decision tree to tell a scheduled sale from a discretionary one.

Most Form 4s are filed on time. A stubborn minority are not. Here is how filing timeliness is distributed, why it happens, and when lateness is worth caring about.

A Rule 10b5-1 plan lets insiders schedule trades in advance. Understanding them is the difference between reading insider selling correctly and being misled by it.

Work out the cost basis, gain or loss, return, and short- vs long-term holding period for a stock sale. Commissions folded in the way the IRS treats them.

Enter a transaction date and get the exact Section 16 filing deadline — two business days later, with US federal holidays and weekends handled. Optionally check whether a filing was late.