By the InsiderAlpha research team · Updated Jul 16, 2026 · Sourced from SEC EDGAR filings
Form 4 and Form 144 are both SEC filings tied to insider activity, and they are easy to confuse. The key distinction is timing and certainty: Form 4 reports a trade that has already happened, while Form 144 is advance notice that an affiliate intends to sell restricted or control securities. A Form 144 is a plan; a Form 4 is a fact.
As covered in our Form 4 guide, Form 4 is filed under Section 16(a) within two business days of an insider buying or selling. It is precise: exact share counts, prices, transaction codes, and resulting ownership. It is the authoritative record of what an insider actually did.
Form 144 is required under Rule 144 when an affiliate (an officer, director, or large shareholder) plans to sell "restricted" or "control" securities above a threshold — more than 5,000 shares or $50,000 within any three-month period. It is filed at or before the time the sell order is placed, and it states the maximum the insider is authorized to sell.
This trips up a lot of investors. A Form 144 says an insider may sell up to a certain amount — it does not mean they did, or that they sold the full amount. Many Form 144 notices are only partially executed, and some are never executed at all. The actual sale, if and when it happens, is what shows up later on Form 4.
Form 144 gives you an early heads-up that selling pressure may be coming, which can be useful context. But never treat a Form 144 as a realized sale — wait for the confirming Form 4. InsiderAlpha tracks both: Form 144 notices for forward-looking context, and Form 4 for the ground truth that drives the signal. Because so many 144 notices are pre-scheduled, they often correspond to Rule 10b5-1 plan selling rather than opportunistic exits.
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