Form 144 Explained: Notices of Proposed Insider Sales

A company insider selling stock is not the same event as a company insider buying it, and the SEC treats them differently in its paperwork. Form 144 is the notice an affiliate files before selling restricted or control securities under Rule 144, and it often arrives before the sale itself shows up in a Form 4. This guide covers who has to file it, what triggers it, and how to query the data.

What is Form 144?

Form 144 is a Notice of Proposed Sale of Securities filed under Rule 144 of the Securities Act of 1933. Rule 144 is the safe harbor that lets holders of restricted securities, and affiliates holding control securities, resell them without registering the resale, once certain conditions are met.

Form 144 is the advance notice piece of that safe harbor. It tells the SEC, before or at the time the sell order is placed, that an affiliate intends to sell a specific number of securities through a specific broker.

Who has to file, and when it is required

Rule 144(h) requires the filing to come from the person for whose account the sale is being made, meaning the selling affiliate, not the issuer. Someone who was an affiliate within the 90 days before the sale is still covered.

Filing is only required once sales cross a threshold. A Form 144 is required when an affiliate's sales under Rule 144 in any three-month period exceed 5,000 shares (or units) or $50,000 in aggregate sale price. Sales at or below both of those limits fall under a de minimis exception and need no filing. Each seller applies this test individually, even when sales must be aggregated with other sellers under Rule 144's aggregation rules.

When a filing is required, it must be made at the time the sell order is placed with the broker, or at the time of the sale if it is made directly to a market maker. Since April 13, 2023, Form 144 for securities of reporting companies must be filed electronically on EDGAR.

What triggers the sale window

Filing Form 144 does not authorize an open-ended sale. The seller must have a bona fide intention to sell within a reasonable time of filing, and Rule 144 gives the seller up to 90 days from the filing date to complete the sale. If the sale does not happen in that window, a new Form 144 is required before selling.

An affiliate's sales also remain subject to Rule 144's volume limits while the person is an affiliate: in any three-month period, sales are capped at the greater of 1% of the company's outstanding shares or the average weekly trading volume over the preceding four weeks, along with the rule's manner-of-sale conditions.

What the filing contains

A gotcha when querying by issuer

Form 144 is filed by the seller, which means the cik on the filing itself is the seller's CIK, not the issuer's. If you want every Form 144 filed against a particular company, filter on the issuer field inside the filing data rather than the top-level CIK. In SecFeed's raw Form 144 data, the issuer's CIK is nested at data.primary_doc.formData.issuerInfo.issuerCik.

Querying Form 144 in code

SecFeed exposes a flattened view of each Form 144 with the seller, relationship, shares, market value, broker, sale date and the past three months of sales already pulled out as top level fields. To find large proposed sales:

curl "https://secfeedapi.com/v1/form-144?flat.aggregateMarketValue__gte=1000000&fields=flat" \
  -H "Authorization: Bearer YOUR_API_KEY"

A flattened row looks like this:

{
  "cik": "1234567",
  "sellerName": "JANE EXAMPLE",
  "relationship": "Director",
  "securityClass": "Common Stock",
  "sharesToBeSold": 15000,
  "aggregateMarketValue": 1425000,
  "broker": "EXAMPLE SECURITIES LLC",
  "approxSaleDate": "2026-10-20"
}

To look up a specific affiliate's filing history by their own CIK:

from secfeed import Client

sf = Client("YOUR_API_KEY")
notices = sf.form_144(cik="1234567", startDate="2026-01-01")
for n in notices:
    print(n["approxSaleDate"], n["sharesToBeSold"], n["aggregateMarketValue"])

How Form 144 relates to Form 4

Both forms involve company insiders, but they report different things. Form 144 is a forward-looking notice of an intended sale, filed only by affiliates and only above the de minimis thresholds. Form 4 is a record of a transaction that already happened, filed by officers, directors and 10% owners for nearly any change in their holdings, with a two business day deadline. Reading them together can show the gap between a stated intention to sell and the completed transaction. You can read every Form 4 transaction in SecFeed through /v1/insider-trading.

Frequently asked questions

Does every insider stock sale require a Form 144?

No. Only affiliates selling restricted or control securities under Rule 144, above the 5,000 share or $50,000 de minimis thresholds, need to file. Many insider sales happen under different circumstances, such as a sale of securities that were never restricted, and would not trigger a Form 144.

Is Form 144 the same as Form 4?

No. Form 144 is a notice of a proposed sale, filed before or at the time the sell order is placed. Form 4 reports a transaction that has already occurred. The same sale by an insider of a reporting company can appear on both: first as a Form 144 notice, then as a completed Form 4 transaction.

How long is a Form 144 notice valid?

The seller has up to 90 days from the filing date to complete the sale under that notice. A new Form 144 is required for sales after that window, or once the previously noticed amount has been sold.

Why does the CIK on a Form 144 point to the seller instead of the company?

Rule 144(h) requires the person making the sale to file the notice, not the issuer. The filing's top-level CIK identifies that seller. The issuer is still recorded inside the filing, in the issuer information section of the form.

Where can I find Form 144 filings for free?

Form 144 filings are public and searchable on SEC.gov through EDGAR company search or full text search, one filer at a time. SecFeed parses the same filings into structured, filterable fields for querying across many sellers or issuers at once.