SEC Form 144 Affiliate Insider Stock Sales: 2026 Filing Guide for Restricted Securities

Building FinanceTrackDaily on top of the SEC EDGAR API, I aggregate filings from roughly 3,400 US-listed companies every trading day. One filing type that surprises beginner investors more than any other is SEC Form 144. People mix it up with Form 4 constantly. They are not the same form, they fire at different points in the trade lifecycle, and the rules around who must file what — and when — are spelled out in Rule 144 of the Securities Act of 1933.

This 2026 guide explains what Form 144 actually is, who has to file it, the share-volume and dollar thresholds, the post-2023 EDGAR-only filing mandate, and how an engineer aggregating SEC data reads these documents in practice. Everything below is educational. None of it is a recommendation to buy, sell, or hold any specific security.

What Is SEC Form 144?

SEC Form 144, formally titled "Notice of Proposed Sale of Securities Pursuant to Rule 144," is a filing required when a company affiliate intends to sell restricted or control securities in the public market. It is a notice of intent — not a confirmation that a sale has happened.

The legal anchor is Rule 144 under Section 4(a)(1) of the Securities Act of 1933. Rule 144 carves out a safe harbor letting affiliates sell their otherwise-restricted shares in the open market without having to register the sale, provided several conditions are met. Form 144 is the paperwork that documents one of those conditions: prior notice to the SEC.

From an engineering perspective, Form 144 is a small, structured document — typically only 2 to 4 pages — that tells the market: "An affiliate of issuer X plans to sell up to N shares within the next 90 days."

Who Must File Form 144?

Form 144 is filed by affiliates of the issuer. Under Rule 144(a)(1), an affiliate is a person who, directly or indirectly, controls, is controlled by, or is under common control with the issuer. In practice, the SEC treats the following parties as affiliates:

• Executive officers — CEO, CFO, COO, General Counsel, and any officer with policy-making authority.
• Directors — every member of the board of directors.
• 10% beneficial owners — any person or entity holding 10% or more of any class of voting equity, per Section 16 of the Securities Exchange Act.
• Family members or trusts sharing a household with an affiliate, where the affiliate is deemed to have indirect control.

Non-affiliates selling restricted stock are generally not required to file Form 144 once their holding period is satisfied. The form is specifically a control-person notice.

When Is Form 144 Required? The 5,000 / $50,000 Threshold

This is the part most retail investors get wrong. Form 144 is only required when an affiliate's planned sale crosses the de minimis threshold set by Rule 144(h):

Rule 144(h) Filing Threshold: A Form 144 must be filed when the proposed sale, combined with all sales of the same class of securities by the same person during the preceding three months, exceeds 5,000 shares OR has an aggregate sale price greater than $50,000.

The threshold is disjunctive — either condition triggers the filing. A CEO selling 4,800 shares at $20 (≈$96,000) hits the dollar threshold and must file. A CEO selling 6,000 shares at $5 (≈$30,000) hits the share threshold and must also file. Aggregation across the 90-day window matters too: small piecewise sales that individually look harmless can cross the line in the aggregate.

Holding Period Rules: 6 Months or 1 Year

Before any sale can be made under Rule 144, the affiliate must satisfy a minimum holding period. The SEC distinguishes between two issuer types:

The clock starts the day the affiliate paid for the securities in full. For employee stock plans, the holding period typically begins on the vesting or exercise date, not the grant date. Restricted Stock Units (RSUs) that vest into common stock generally start the holding clock at vesting.

Volume Limitations Under Rule 144(e)

Even after the holding period clears and Form 144 is filed, the affiliate cannot dump unlimited shares. Rule 144(e) caps how much can be sold in any rolling three-month window:

• Equity securities of an issuer listed on a national exchange: the greater of (a) 1% of the outstanding shares of that class, or (b) the average weekly reported trading volume during the four calendar weeks preceding the Form 144 filing.
• OTC equity securities: 1% of the outstanding shares of that class (no trading-volume alternative).
• Debt securities: 10% of a tranche or class outstanding.

For a large-cap stock with billions of shares outstanding, the four-week trading-volume number usually controls. For a small-cap, the 1% outstanding-shares cap usually controls. Building a Form 144 parser, I learned to compute both ceilings and surface the lower one — that is the binding limit for the affiliate.

EDGAR-Only Filing: The April 2023 Mandate

For decades, Form 144 could be filed on paper. That changed. In June 2022, the SEC adopted final rule release 33-11070, mandating electronic submission of Form 144 through the EDGAR system. Compliance became mandatory effective April 13, 2023. Paper Form 144s are no longer accepted.

This shift mattered enormously for anyone aggregating insider activity. Before April 2023, paper Form 144s landed at SEC HQ with a multi-day scanning lag and often never appeared in machine-readable form. After April 2023, every Form 144 is submitted as a structured filing through EDGAR — with timestamps accurate to the second, and a stable accession number identifying the document.

From a data-engineering standpoint, the practical change was that I could finally build a Form 144 watcher with the same daily polling cadence I already use for Form 4 and Form 13F. Before the EDGAR mandate, that was effectively impossible without scanning paper PDFs.

Form 144 vs. Form 4: The Key Difference

This is the confusion I see most often. The two forms relate to insider trading but they are not redundant.

The simple way to remember it: Form 144 is forward-looking, Form 4 is backward-looking. An affiliate often files both — a Form 144 announcing the planned sale, then a Form 4 once the sale settles. Aggregating both gives a fuller picture: who said they were going to sell, who actually did, and the gap between intent and execution.

How to Read a Form 144 on EDGAR

Every Form 144 on EDGAR contains a few key sections. Walking through what is actually in the document, top to bottom:

1. Issuer name and address — the public company whose shares are being sold.
2. Person for whose account the securities are to be sold — the affiliate's name, relationship to the issuer (e.g., "CEO"), and address.
3. Description of securities to be sold — class of stock, broker, approximate sale date, number of shares, and aggregate market value.
4. Securities to be sold for the account of the person named above — date of acquisition, nature of acquisition (e.g., "RSU vesting," "stock option exercise"), and date the holding period clock started.
5. Securities sold during the past three months — a schedule of every prior sale by the same affiliate in the rolling 90-day window. This is what feeds the aggregation rule.
6. Signature — the affiliate (or duly authorized agent) certifies under penalty of perjury that the information is accurate.

EDGAR exposes Form 144 filings via the standard full-text search at https://efts.sec.gov/LATEST/search-index?q=%22form+144%22&forms=144 and through company-specific filing pages. The form type code on EDGAR is simply 144.

Engineer Notes — What Aggregating Form 144 Reveals

Working through several months of Form 144 filings while building FinanceTrackDaily, three structural observations stood out:

1. Form 144 volume spikes around earnings. Affiliate sales are clustered into 4-week trading windows that open after each quarterly earnings release, when blackout periods lift. Aggregating Form 144s by week shows a recurring shape: heavy activity in the second and third weeks after a 10-Q or 10-K, near-zero in the two weeks before the next earnings call.

2. The "intent gap." Comparing Form 144 (intent) against the Form 4 (execution) for the same affiliate, the median gap between the filed intent and the first executed sale was several trading days — not always immediate. Some Form 144s never produce a Form 4 at all because the affiliate changed plans within the 90-day window. The form is a notice, not a binding commitment.

3. RSU vesting drives a big share of filings. A large fraction of Form 144 filings list "vesting of restricted stock units" as the source of the shares being sold. These are routine sell-to-cover transactions that fund the tax withholding on vested RSUs — they are not a directional signal about the affiliate's view of the stock. Reading too much into a single Form 144 without that context is exactly the mistake I want this guide to help readers avoid.

Common Mistakes and Penalties

The SEC and FINRA take Rule 144 compliance seriously. Common compliance failures include:

• Failing to file when required. Affiliates who exceed the 5,000-share / $50,000 threshold without filing Form 144 lose the Rule 144 safe harbor. The sale can then be treated as an unregistered distribution under Section 5 of the Securities Act, which carries civil penalties.
• Filing a Form 144 but breaching the volume cap. Selling above the Rule 144(e) ceiling — even with a filed Form 144 — also forfeits the safe harbor.
• Holding-period miscount. Treating the grant date instead of the vesting date as the start of the holding period is a frequent error for employee-equity sales.
• Failure to aggregate. Three separate $20,000 sales over 90 days exceed the $50,000 dollar threshold in aggregate and trigger a filing requirement, even though each individual sale does not.

FINRA member firms acting as broker for the sale have their own due-diligence obligations under FINRA Rule 4515 and related rules. They are required to verify the seller's status as an affiliate, the holding period, the volume limit, and the prior 90-day sales schedule before executing the order. In practice, the broker often is the party that prepares and submits Form 144 on behalf of the affiliate.

Frequently Asked Questions

Is Form 144 the same as a Section 16 filing?

No. Section 16 of the Exchange Act of 1934 governs Forms 3, 4, and 5 — covering officers, directors, and 10% holders. Form 144 is grounded in Rule 144 under the Securities Act of 1933. The two regimes overlap in who they cover but not in what they require.

Does a Form 144 mean the insider is bearish on the stock?

Not on its own. Many Form 144 filings represent routine RSU sell-to-cover, scheduled 10b5-1 plan executions, diversification, or estate planning. Treating any single Form 144 as a directional signal is unsupported by the structure of the filing.

How long is a Form 144 valid?

The form contemplates sales within roughly 90 days of filing. If the affiliate has not sold all the shares listed and wants to continue selling beyond that window, a new Form 144 must be filed.

Can I find Form 144 filings on EDGAR full-text search?

Yes. EDGAR full-text search supports filtering by form type. Filter for form type 144 at https://efts.sec.gov/LATEST/search-index?forms=144 to see recent submissions across all issuers.

Are 10b5-1 plans related to Form 144?

They interact. A 10b5-1 plan is a pre-arranged trading plan that gives an affiliate an affirmative defense against insider-trading liability. Sales executed under a 10b5-1 plan still must comply with Rule 144 — including the Form 144 filing, holding-period, and volume-cap requirements — when those thresholds are crossed.

Conclusion

SEC Form 144 is one of the cleaner, more useful filings on EDGAR — a structured 2-to-4-page notice that tells the market when affiliates intend to sell restricted or control securities. Pair it with the corresponding Form 4 once the sale settles, and you have a reasonably complete picture of insider activity. Read in isolation, a single Form 144 is rarely a meaningful signal, especially when the underlying source is RSU vesting.

For an engineer aggregating SEC data, the April 2023 EDGAR mandate was the unlock. Every Form 144 is now machine-readable, timestamped, and addressable by accession number — making it a first-class citizen of the SEC filings ecosystem alongside the 10-K, 10-Q, 8-K, Form 4, Schedule 13D/G, and Form 13F filings I have written about elsewhere on FinanceTrackDaily.