Beneficial Ownership Reporting and Section 16: Schedules 13D and 13G, Group Formation, and Short-Swing Profits

Document type: Article Practice area: Corporate — Securities Regulation Jurisdiction: United States (federal securities law) Last reviewed: 5 September 2026

Two regimes, two purposes

Public company ownership disclosure sits on two statutory pillars that people constantly confuse.

Section 13(d), codified at 15 U.S.C. § 78m(d), is a market transparency rule. It requires a person who acquires beneficial ownership of more than 5% of a registered class of equity securities to disclose who they are, how much they own, where the money came from, and — the item that matters — what they intend to do. Its origin is the Williams Act, and its purpose is to prevent a bidder from accumulating a control block in secret and presenting stockholders with a fait accompli.

Section 16, codified at 15 U.S.C. § 78p, is an anti-insider-trading rule that operates without proof of insider trading. It applies to officers, directors, and holders of more than 10% of a registered class. It requires prompt reporting of every transaction, and it requires disgorgement of any profit realized from a purchase and a sale (or a sale and a purchase) within a six-month window. It is strict liability: no scienter, no materiality, no proof that anyone knew anything.

The two overlap — a 10% holder files under both — but they answer different questions and forgive different mistakes. Section 13(d) is about telling the market your plans. Section 16 is about a mechanical rule that takes your money whether or not you did anything wrong.

Part one: Sections 13(d) and 13(g)

Who is a beneficial owner

Beneficial ownership under Section 13(d) turns on voting power or investment power, not on economic interest. A person beneficially owns securities if they have or share, directly or indirectly, through any contract, arrangement, understanding, relationship, or otherwise:

Voting power, meaning the power to vote or direct the voting; or
Investment power, meaning the power to dispose or direct the disposition.

A person may beneficially own securities they have no economic interest in — an investment adviser with discretionary authority over client accounts, for example — and may have substantial economic exposure without beneficial ownership, which is the derivatives problem discussed below.

Beneficial ownership also includes securities the person has the right to acquire within sixty days, through exercise of an option or warrant, conversion, revocation of a trust, or termination of a power of attorney.

The 5% threshold and the filing obligation

A person who acquires beneficial ownership of more than 5% of a class of equity securities registered under Section 12 must file a Schedule 13D within the prescribed period after crossing the threshold, and must amend it promptly upon any material change — including any acquisition or disposition of 1% or more of the class, and any change in the plans or proposals disclosed.

The disclosure items are the operative part:

Item 1–2: the security and the issuer; the identity and background of the filing person, including criminal and securities-law history;
Item 3: source and amount of funds, including whether any part was borrowed, and if so from whom and on what terms;
Item 4: purpose of the transaction. This is the item that matters and the item that generates litigation. The filer must state whether it has any plans or proposals relating to an extraordinary transaction, a sale of assets, a change in the board or management, a change in capitalization or dividend policy, a change in the charter or bylaws, delisting, deregistration, or any similar action;
Item 5: interest in the securities, including transactions in the prior sixty days;
Item 6: contracts, arrangements, understandings, or relationships with respect to the securities — including derivatives;
Item 7: exhibits, including any joint filing agreement and any relevant contracts.

The 13G alternatives

Three categories may file the shorter Schedule 13G instead:

Qualified institutional investors. Registered investment advisers, broker-dealers, banks, insurance companies, and similar institutions that acquired the securities in the ordinary course of business and not with the purpose or effect of changing or influencing control.

Passive investors. Any person holding less than 20% who acquired and holds without the purpose or effect of changing or influencing control.

Exempt investors. Persons who crossed 5% without making an acquisition subject to Section 13(d) — for example, by holding since before the company registered, or through a reduction in outstanding shares.

The dividing line is control intent. A 13G filer who develops a control purpose must convert to a Schedule 13D, and — critically — is subject to a cooling-off period during which it may not vote or acquire additional securities. The conversion moment is a genuine trap: an institution that begins pressing management on strategy has to decide whether it has crossed from engagement into control-influencing conduct, and the answer determines its filing status, its ability to trade, and its litigation exposure.

Practical guidance for institutions: maintain a written engagement policy distinguishing permissible stewardship (voting, discussing governance and performance generally, publicly stating views) from control-influencing conduct (nominating directors, demanding board seats, proposing a transaction, forming a group to change control). Document the analysis when an engagement escalates.

Groups: the doctrine that surprises people

Section 13(d)(3) provides that when two or more persons act as a partnership, limited partnership, syndicate, or other group for the purpose of acquiring, holding, or disposing of securities of an issuer, the group is deemed a "person." If the group collectively owns more than 5%, the group must file.

GAF Corp. v. Milstein, 453 F.2d 709 (2d Cir. 1971) established the breadth of this. Members of a family who held convertible preferred stock and agreed among themselves to seek representation on the board formed a group, even though none of them acquired any additional shares after forming it. The court held that Section 13(d)(3) reaches a group formed to hold as well as to acquire, reasoning that a control block assembled from existing holdings is exactly as significant to the market as one assembled by purchase.

What creates a group:

An agreement to act together with respect to the securities — voting, acquiring, disposing, or seeking control;
The agreement need not be written, need not be enforceable, and need not involve any acquisition;
Concerted action pursuant to an understanding suffices.

What does not, standing alone:

Parallel investment decisions reached independently;
Attending the same conference, or holding the same view;
Ordinary discussions among stockholders about a company's performance;
An investment adviser's aggregated client holdings, which are aggregated for other reasons.

The "wolf pack" problem. Activists who tip other funds before accumulating, and those funds then buy, present the hardest question. If there is an agreement or understanding to act together, there is a group. If the second fund simply drew its own conclusion from public information, there is not. The distinction turns on evidence of coordination, which is why activist campaigns generate document discovery into communications among funds.

CSX and the derivatives question

The most consequential modern case is CSX Corp. v. Children's Investment Fund Management (UK) LLP, 654 F.3d 276 (2d Cir. 2011).

Two hedge funds accumulated large economic exposure to CSX through cash-settled total return swaps — instruments giving them the economic return on the shares without the right to vote or dispose of them. Their counterparty banks hedged by buying actual shares. The funds also, CSX alleged, coordinated with each other.

The questions: did the swaps make the funds beneficial owners of the hedge shares? And did the funds form a group?

The district court found both. On appeal, the Second Circuit affirmed the group finding and, on the swap question, produced a fractured result: the panel did not definitively resolve whether cash-settled swaps alone confer beneficial ownership, with concurring and dissenting opinions taking different views. The court affirmed the declaratory judgment but declined to enjoin the funds from voting, noting that the violations had been cured by disclosure.

Where this leaves practitioners. The law is genuinely unsettled on whether a cash-settled derivative, without more, creates beneficial ownership. What is clear:

A derivative that gives the holder the right to acquire the underlying shares — physical settlement at the holder's election — creates beneficial ownership.
A derivative accompanied by an understanding that the counterparty will vote as directed or will sell the hedge to the holder creates beneficial ownership.
Item 6 requires disclosure of derivatives regardless. A filer who omits its swap position from Item 6 has a disclosure violation independent of the beneficial ownership question.
Regulatory attention has continued, and the sensible course is to disclose economic exposure fully rather than to litigate the boundary.

Remedies for a violation

Rondeau v. Mosinee Paper Corp., 422 U.S. 49 (1975) is the essential case on remedies. A holder crossed 5% and filed late. The target sued for an injunction. The Supreme Court held that injunctive relief requires irreparable harm, and a late filing that had been cured — with the market now fully informed — caused none. The Court emphasized that Section 13(d) protects investors, not incumbent management, and refused to convert a disclosure statute into a takeover defense.

Practical consequences:

The usual remedy for a late or deficient filing is a corrective filing. Courts order disclosure, not divestiture.
A "sterilization" remedy — enjoining the violator from voting — is available in principle but rarely granted, and CSX declined it where the violation had been cured.
The Commission may bring an enforcement action, and does, with civil penalties.
Targets can obtain real value from the litigation even without a remedy: discovery into coordination among funds, and the delay itself.

Part two: Section 16

Who is covered

Directors of an issuer with a class of equity registered under Section 12;
Officers, defined functionally as the president, principal financial officer, principal accounting officer, any vice president in charge of a principal business unit, division, or function, and any other person who performs a policy-making function — regardless of title; and
Beneficial owners of more than 10% of a registered class, determined under Section 13(d) principles.

The officer definition is a trap. Title is not determinative. A "Senior Vice President, Strategy" who sits on the executive committee and makes policy is a Section 16 officer; a "Vice President, Northeast Region" with a large title and no policy role is not. Issuers should maintain a current list of Section 16 officers, reviewed annually and on every organizational change, because a person who was an officer but never filed has an unreported position and a potential short-swing exposure.

The reporting requirements

Form	When	What
Form 3	Within 10 days of becoming an insider (or at registration)	Initial statement of holdings
Form 4	Before the end of the second business day following the transaction	Changes in beneficial ownership
Form 5	Within 45 days after fiscal year end	Transactions exempt from Form 4 and any previously unreported transactions

Forms are filed electronically and posted publicly, and the issuer must post them on its website. Late Form 4 filings are disclosed in the proxy statement, which is the practical enforcement mechanism — nobody wants a table of delinquent filings under their name.

The short-swing profit rule

Section 16(b) provides that any profit realized by an insider from any purchase and sale, or any sale and purchase, of the issuer's equity securities within any period of less than six months inures to and is recoverable by the issuer.

Four things about this rule surprise people every time:

1. It is strict liability. No intent, no possession of information, no materiality. An officer who buys shares because they believe in the company and sells five months later for an unrelated reason owes the profit.

2. The computation is designed to maximize recovery, not to reflect economic reality. Courts match the lowest purchase price with the highest sale price within any six-month window, then the next lowest with the next highest, and so on, ignoring which shares were actually sold and ignoring losses. An insider who lost money overall can owe a substantial "profit." This is deliberate: the rule is prophylactic, and a computation that netted losses would let insiders trade around it.

3. Any stockholder may sue. The claim belongs to the issuer, but if the issuer does not sue within sixty days of a demand, any security holder may sue on its behalf — and recover attorneys' fees from the recovery. This has produced a specialized plaintiffs' bar that monitors Form 4 filings for matchable transactions.

4. Standing survives the plaintiff's loss of shares. Gollust v. Mendell, 501 U.S. 115 (1991) held that a plaintiff who owned shares when suit was filed retained standing after a merger converted the shares into stock of the parent, because the plaintiff retained a continuing financial interest in the outcome.

The 10% holder rules that differ

For 10% holders — but not for officers and directors — three special rules apply.

The transaction that crosses 10% does not count. Foremost-McKesson, Inc. v. Provident Securities Co., 423 U.S. 232 (1976) held that a person is liable only if they were a 10% holder before the purchase. The purchase that takes someone from 0% to 30% is not a matchable purchase, because the statute reaches a person who is a beneficial owner "at the time of the purchase and sale."

A sale that drops the holder below 10% before the second transaction breaks the match. Reliance Electric Co. v. Emerson Electric Co., 404 U.S. 418 (1972) upheld a two-step sale: Emerson sold enough to fall below 10%, then sold the rest, and only the first sale was matchable. The Court accepted that the structure was deliberately designed to avoid liability, holding that the statute's terms controlled.

The rules do not apply to officers and directors in the same way. An officer or director is covered for transactions within six months of ceasing to serve, and the "before the purchase" limitation does not help them.

Unorthodox transactions

Kern County Land Co. v. Occidental Petroleum Corp., 411 U.S. 582 (1973) addressed a defeated tender offeror that ended up with a profit through an involuntary exchange in a defensive merger it had opposed. The Court applied a pragmatic approach: where a transaction is "unorthodox," involuntary, and unaccompanied by any possibility of speculative abuse — the insider had no access to inside information and no control over the transaction — Section 16(b) does not apply.

This is a narrow exception and courts have kept it narrow. It applies to genuinely involuntary transactions where the insider could not have used inside information. Do not rely on it for a voluntary transaction that merely feels unfair.

Deputization

Blau v. Lehman, 368 U.S. 403 (1962) considered whether a partnership was liable when one of its partners served on the issuer's board. The Court held that a partnership is not automatically a director, but may be liable if the partner was "deputized" to serve on the partnership's behalf. The finding is factual, and the evidence there did not support it.

Why this matters now. Private equity and venture funds routinely place partners on portfolio company boards. If the partner is deputized — serving for the fund, reporting to it, acting on its behalf — the fund is a Section 16 insider and its trading is matchable against the partner's. Funds structure around this by documenting that the individual serves in a personal capacity, but the analysis is substantive rather than formal, and a fund with a board designation right in a stockholders agreement has a difficult argument.

Exemptions that work

Most compensation transactions can be exempted, which is why practice focuses heavily on getting the exemption right.

Rule 16b-3 exempts transactions between the issuer and its officers and directors — grants, awards, and dispositions to the issuer — if approved in advance by:

The board; or
A committee composed solely of two or more non-employee directors; or
The stockholders; or, for acquisitions, if the securities are held for six months.

This is the single most important operational rule in Section 16 practice. Every equity grant, every option exercise settled with the issuer, every share withheld for taxes, and every repurchase from an insider should be approved in advance by a properly constituted committee, with the approval documented specifically.

The recurring failure: a grant approved by a committee that includes a director who is not a "non-employee director" as defined, or approved by an officer under delegated authority rather than by the board or a qualifying committee. The exemption fails, the transaction is matchable, and a plaintiff finds it in the Form 4.

Other exemptions cover certain acquisitions from the issuer, stock splits and dividends, bona fide gifts (reportable on Form 5 but not matchable), and certain transactions in employee benefit plans.

Rule 10b5-1 plans and Section 16

A Rule 10b5-1 trading plan provides an affirmative defense to insider trading liability under Rule 10b-5. It provides no defense whatever under Section 16(b). Transactions executed under a plan are still purchases and sales and are still matched. Insiders and their advisers routinely confuse this. A plan that sells quarterly, combined with an option exercise or an open-market purchase, produces a match.

Attribution: whose shares are yours

Both regimes attribute securities held by others, and the attribution rules are where careful people still get caught.

Family and household. For Section 16, a person is presumed to beneficially own securities held by immediate family members sharing the same household — spouse, children, stepchildren, grandchildren, parents, grandparents, siblings, and in-laws in each of those categories. The presumption can be rebutted, but rebutting it requires facts, not assertion. An officer whose adult child lives at home and trades their own account has a reporting problem they probably do not know about.

Trusts. A trustee with voting or investment power over portfolio securities generally has beneficial ownership. A beneficiary with a pecuniary interest may have reportable ownership under Section 16 even without power. Family trusts, grantor trusts, and irrevocable trusts each require separate analysis, and the answer differs between the 13(d) and Section 16 frameworks — which is the point most often missed. The same shares can be reportable under one regime and not the other.

Controlled entities. Securities held by a corporation, partnership, or LLC the insider controls are attributed. For funds, the general partner, the investment manager, and the individuals who control them are each analyzed separately, which is why a single fund position produces a filing by four or five entities in a joint filing group.

Pledges and margin. A pledge is generally not a disposition, but the pledgee's rights on default matter, and many issuers now prohibit or restrict pledging by insiders as a governance matter. Disclose pledged shares; the proxy advisory firms ask.

Derivatives, again. For Section 16, derivative securities are reported and are matchable — options, warrants, convertibles, and security-based swaps. The Section 16 treatment is broader than the unsettled Section 13(d) treatment: a cash-settled derivative on the issuer's equity held by an insider is generally reportable, and the acquisition or disposition of the derivative is the matchable event rather than the eventual settlement.

Practical instruction. Every insider should complete an annual questionnaire that asks, in plain terms: who lives in your household and do they hold company stock; what trusts hold company stock and what is your role; what entities do you control and do they hold company stock; do you hold any option, swap, or other instrument referencing company stock; and are any of your shares pledged. Most reporting failures are attribution failures, and most attribution failures are questionnaire failures.

The interaction between the regimes

A large holder is often subject to both, and the regimes pull in different directions.

A 13G filer crossing 10% becomes a Section 16 insider. Institutions that hold above 10% in the ordinary course — index managers, in particular — face a real administrative burden and rely on careful structuring and the exemptions available for ordinary-course institutional activity.

An activist crossing 10% loses trading flexibility for six months after every purchase, which is often decisive against crossing at all. The calculus is: how much additional voting power does the increment buy, against the cost of being unable to sell into a rising market.

A 13D filer that becomes a director — or whose designee becomes a director, if deputized — is subject to Section 16 regardless of percentage. Board representation obtained through a settlement therefore converts a trading-flexible position into a constrained one, and the settlement agreement's terms are evidence on the deputization question.

A Section 16 insider crossing 5% must file a Schedule 13D or 13G, and the Item 4 purpose statement will be read against their role. A chief executive who accumulates 6% and files a 13D stating no plans, while simultaneously discussing a buyout with a sponsor, has a serious problem.

Timing coordination. Because the deadlines differ — Form 4 within two business days, Schedule 13D within its own period, amendments promptly — a single transaction can trigger several filings with different clocks. Maintain one calendar covering both regimes rather than two calendars maintained by different people.

Worked example one: an activist accumulates

The fund. Halvard Point Capital, a $4 billion activist fund run by Sunniva Halvard, identifies Petrachek Logistics as undervalued. Petrachek has 62 million shares outstanding.

Week 1–3. Halvard Point buys 2.9 million shares, 4.7%, on the open market. No filing is required below 5%. It also enters cash-settled swaps referencing an additional 1.8 million shares.

The first question: do the swaps count? Under CSX, this is genuinely unsettled. Halvard Point's counsel, Emeka Onwuachi, gives the advice that experienced counsel gives: treat the economics as if they might count, and disclose them in any event. The swaps have no physical settlement right and no understanding with the counterparty about voting or selling the hedge, which is the best position to be in — but the position is defensible, not certain.

Week 4. Halvard Point buys another 400,000 shares, crossing 5%. The Schedule 13D clock starts.

What Item 4 must say. Halvard Point has, in fact, prepared a presentation arguing for the divestiture of a segment and the addition of two directors. It must say so. An Item 4 stating that the shares were acquired "for investment purposes" and that the filer "may from time to time engage with management" would be false, and the presentation would be the exhibit proving it.

Onwuachi drafts Item 4 to disclose: the fund's belief that the shares are undervalued; its intention to engage with the board regarding capital allocation and the segment; that it may seek board representation; that it may acquire or dispose of shares; and that it may take any of the actions enumerated in the item. Item 6 discloses the swaps in full, including notional, counterparty type, and settlement terms.

Week 6 — the group question. Halvard Point's head of research speaks with two other funds about Petrachek. This is the moment that decides whether there is a group.

If the conversation is an exchange of views about a public company, there is no group. If it includes an understanding that the other funds will buy and support Halvard Point's nominees, there is — and the group's aggregate holdings, which exceed 5%, trigger a joint filing obligation, with each member liable for the group's disclosure.

Onwuachi's instruction to the team is specific and worth quoting in substance: do not ask another holder what they will do, do not tell them what we will do before it is public, do not agree on anything, and assume every communication will be produced in litigation. GAF v. Milstein means that an agreement to hold and act together is enough; no purchase is required.

Week 9 — Section 16. Halvard Point continues buying and crosses 10%. It is now a Section 16 insider.

Form 3 due within 10 days.
Form 4 for every subsequent transaction, within two business days.
The purchase that crossed 10% is not matchable, under Foremost-McKesson.
But every purchase after that is. If Halvard Point sells any shares within six months of any post-10% purchase, it owes the matched profit to Petrachek.

The consequence for strategy. Halvard Point cannot trade around its position while above 10%. If the campaign succeeds and the stock rises, it cannot take profits for six months after its last purchase. Many activists deliberately stay below 10% for exactly this reason, accepting a smaller position in exchange for trading flexibility. Halvard Point decides to cross anyway, because the additional voting power matters more.

Week 20 — the settlement. Petrachek agrees to add two Halvard Point nominees and to review the segment. Halvard Point amends its Schedule 13D promptly to disclose the agreement and attaches it as an exhibit.

One more Section 16 point. If a Halvard Point partner joins the Petrachek board and is deputized under Blau v. Lehman, the fund's trading and the director's trading are aggregated for matching purposes. The fund documents that the nominees serve in their personal capacities — but with a board designation right in the settlement agreement, that position is weak, and Onwuachi advises the fund to assume Section 16 applies and to plan its trading accordingly.

Worked example two: the inadvertent short-swing

The insider. Teodora Vasilenko is Chief Technology Officer of Rendlesham Semiconductor, a Section 16 officer.

March 4. Rendlesham grants her 40,000 restricted stock units. The grant was approved by the Compensation Committee, whose three members are all non-employee directors. Exempt under Rule 16b-3. Reported on Form 4 within two business days.

April 22. Vasilenko buys 5,000 shares in the open market at $61, because she believes the stock is cheap. Not exempt. A purchase.

June 10. A tranche of previously granted RSUs vests. Rendlesham withholds 3,100 shares to cover taxes. This is a disposition to the issuer. If the withholding was approved in advance by the Compensation Committee — either specifically or through the plan's terms as approved — it is exempt under Rule 16b-3. If it was handled administratively by the stock plan department under delegated authority, it is not.

July 30. Vasilenko sells 8,000 shares at $79 under a Rule 10b5-1 plan adopted eight months earlier.

The analysis.

The April 22 purchase at $61 and the July 30 sale at $79 are within six months. Matched. 5,000 shares × $18 = $90,000 owed to Rendlesham.
The 10b5-1 plan is irrelevant to this. It defends against Rule 10b-5, not Section 16(b).
The March 4 grant is exempt and not matchable.
The June 10 tax withholding is the live question. If the exemption fails, it is a sale that can be matched against the April 22 purchase — and the matching rules would pair the lowest purchase with the highest sale, meaning a plaintiff would construct the most expensive combination available.

What happens next. A plaintiff's firm monitoring Form 4 filings identifies the match within weeks, sends a demand to Rendlesham, and files suit if the company does not act within sixty days. Rendlesham's general counsel confirms the calculation, and Vasilenko pays the company $90,000. She receives no tax deduction of any comfort, and the payment is disclosed.

What should have happened. Rendlesham's insider trading policy should have required pre-clearance of every insider transaction against a Section 16 matching calendar maintained by the legal department — a simple record of every insider's purchases and sales for the trailing six months, checked before any transaction is approved. The April purchase would have been flagged as creating a six-month blackout against sales at a higher price, and Vasilenko would have been told.

And the withholding question should have been closed years earlier, by having the Compensation Committee approve, in the plan and in each award agreement, the withholding of shares to satisfy tax obligations. That single approval, obtained once, exempts every future withholding.

Practice notes

For issuers.

Maintain a current Section 16 officer list, reviewed annually and on every reorganization. Apply the functional test, not titles.
Maintain a matching calendar for every insider, checked before pre-clearance.
Get Rule 16b-3 approvals right: a committee of two or more non-employee directors, approving in advance, with the approval documented specifically — including tax withholding and dispositions to the issuer.
File Forms 4 on time. Late filings appear in the proxy statement.
Educate insiders that a 10b5-1 plan does not defend against Section 16(b).

For large holders.

Decide early whether you are 13D or 13G, and document the analysis. Escalating engagement can force a conversion, with a cooling-off period.
Draft Item 4 to match reality. An inaccurate purpose statement is the most dangerous item in the schedule.
Disclose derivatives in Item 6 regardless of the beneficial ownership question.
Assume every communication with another holder will be produced. Groups are formed by understandings, not by contracts.
Consider whether crossing 10% is worth the Section 16 constraint. For many funds it is not.
Amend promptly. "Promptly" means days, not weeks, and a stale schedule during an active campaign is an easy target.

For directors and officers.

Pre-clear everything, including gifts, transfers to trusts, and transactions by family members and controlled entities.
Understand that a purchase creates a six-month constraint on selling higher, and vice versa.
Remember that beneficial ownership includes shares held by immediate family sharing your household and by entities you control.
Report within two business days. The deadline is short and the calendar is unforgiving.

What issuers actually do with this information

Ownership filings are not merely a compliance obligation for the filer; they are an intelligence source for the issuer, and companies that read them well see campaigns coming.

Monitor the register continuously. Stock surveillance services track settlement data and identify accumulating positions before a Schedule 13D appears. A position building through several nominees, or unusual options activity, is a signal.

Read every 13G conversion. A holder converting from 13G to 13D has, by definition, formed a control purpose. That filing is the clearest possible advance notice.

Read Item 4 carefully, and read what it does not say. Sophisticated filers disclose the maximum range of possible actions to preserve flexibility, which makes the boilerplate uninformative. The informative parts are the specific statements: a reference to a particular segment, a named transaction, a stated view on capital allocation.

Read Item 6 for derivatives. Economic exposure well above the reported voting position tells you the holder's real stake and its likely willingness to fight.

Track group indicators. Multiple funds appearing in the same quarter, common counsel, coordinated public statements, or shared research are all worth noting. If a group exists and has not filed, the issuer has a claim — and, more usefully, a discovery vehicle.

Use the information in engagement, not in litigation, first. The most common productive response to a new 13D is a call from the chair or lead independent director. Litigation over a disclosure defect rarely changes an outcome, as Rondeau makes clear, but it can buy time and produce documents.

A word of caution. A target that sues over a technical Section 13(d) defect without irreparable harm is asking a court to convert an investor protection statute into a takeover defense, which courts have declined to do for fifty years. Bring the claim when the disclosure defect is real and material — an inaccurate Item 4, an unfiled group, an undisclosed derivative position — and be prepared for the remedy to be a corrective filing rather than an injunction.

Short-swing computation worked through

Because the matching rule is counterintuitive, it is worth seeing the arithmetic.

The transactions. An insider, over five months:

Date	Transaction	Shares	Price
1 Feb	Buy	2,000	$40
15 Mar	Buy	3,000	$55
2 May	Sell	2,500	$70
20 Jun	Sell	1,500	$48

The insider's actual economics. Total purchased: 5,000 shares for $245,000. Total sold: 4,000 shares for $247,000. Average cost $49, average sale price $61.75. The insider made money, but modestly, and still holds 1,000 shares.

The Section 16(b) computation. Match the lowest purchase against the highest sale, then repeat, ignoring which shares were actually sold and ignoring losing pairs:

Lowest purchase: 1 Feb at $40 (2,000 shares). Highest sale: 2 May at $70 (2,500 shares). Match 2,000 shares. Profit: 2,000 × $30 = $60,000.
Remaining highest sale: 2 May at $70 (500 shares left). Next lowest purchase: 15 Mar at $55. Match 500 shares. Profit: 500 × $15 = $7,500.
Remaining sale: 20 Jun at $48 (1,500 shares). Remaining purchase: 15 Mar at $55 (2,500 shares). This pairing produces a loss and is therefore ignored.

Total recoverable: $67,500.

The insider's real gain across all four transactions was roughly $10,000 on realized trades. The statutory "profit" is nearly seven times that, and the loss-producing pair is simply disregarded.

Two lessons. First, the computation is a penalty formula, not an accounting. Second — and this is the operational point — any purchase creates a six-month exposure to every subsequent sale at a higher price, and any sale creates a six-month exposure to every subsequent purchase at a lower price. An insider who buys today cannot safely sell above that price for six months, in any amount, for any reason.

That is why the only workable control is a matching calendar consulted before every pre-clearance, and why insider trading policies should require pre-clearance of transactions by household family members and controlled entities as well.