MGNX SEC Filing News — MacroGenics, Inc.

Latest SEC filings for MacroGenics, Inc. (MGNX) explained in plain English. Covers insider buying and selling (Form 4), proposed insider sales (Form 144), material company events (8-K), and quarterly & annual reports (10-Q / 10-K). StrongBuyAnalytics provides navigation and brief excerpts or summaries; original filings remain at the SEC/source links and were authored by their filers, not StrongBuyAnalytics. Filing dates shown are source dates. Coverage and detection can be delayed or incomplete because of SEC availability, amendments, parsing, caching, or outages. Latest source filing date shown: 2026-10-07.

MacroGenics, Inc., a clinical-stage biopharmaceutical company, discovers, develops, manufactures, and commercializes antibody-based therapeutics for the treatment of cancer in the United States. The company's product pipeline includes lorigerlimab, a bispecific DART molecule that targets checkpoint inhibitors PD-1 and CTLA-4 for the treatment of mCRPC and docetaxel that is in phase 2 clinical trials, as well as for the treatment of platinum-resistant ovarian cancer and clear cell gynecologic can…
Sector: Healthcare Industry: Biotechnology Market Cap: $207.0M CIK: 1125345
20
Total Filings
0
Bullish Classifications
1
Bearish Classifications
9
Insider Transactions
5
Material Events (8-K)
1
Periodic Reports
Rule-based classifications for MGNX currently lean bearish. Of the 20 filing records displayed, 1 carry bearish classifications (such as insider sales or negative 8-K disclosures) versus 0 bullish. This does not necessarily signal fundamental deterioration — insiders sell for many reasons — but it is worth monitoring alongside the company's core financial metrics.
MGNX Filing Activity Snapshot 2026-05-20 — 2026-10-07
Insider Transactions (Form 4)
0 buys vs 1 sell
Net insider selling in this period — insiders sell for many reasons beyond conviction.
Largest Form 144 Filing
$175.7K
Jay Siegel · 2026-08-17
42,080 shares · Form 144
Form 144 Notices
5
Proposed insider sales filed — Form 144 is a notice of intent, not a confirmed transaction. Actual sales are confirmed via Form 4.
Insider Transactions 9 · Forms 3, 4 and 5

A Form 4 is filed within two business days of a company insider — an officer, a director, or a holder of more than ten percent of the stock — changing their position in the shares. All 9 filings in this group are Form 4s for MacroGenics, Inc.

The difficulty with reading these filings as a group is that a single form type covers transactions that mean entirely different things. An executive spending their own money to buy stock and an executive having shares withheld to pay tax on a vesting grant both appear as a Form 4. Every filing below is therefore tagged with the nature of the underlying transaction, taken from the transaction code reported on the form itself.

Across the 9 insider filings shown, the breakdown is 5 compensation award, 3 option exercise and 1 open-market sale. 1 of them involved a discretionary open-market trade; the rest are compensation and administrative mechanics.

What each transaction type means

Compensation award ×5
Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.
Option exercise ×3
The insider converted options into shares. The exercise price was fixed when the options were granted, so the timing usually tracks an expiry schedule.
Open-market sale ×1
The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.
Form 4 Option exercise Tax / Compensation Filing 2026-10-07

MGNX insider Form 4 filed for equity award, exercise, or tax withholding

Bonvini Ezio (Sr VP, Research & CSO) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

The insider converted options into shares. The exercise price was fixed when the options were granted, so the timing usually tracks an expiry schedule.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 8,000 $2.60 $20.8K
M Option exercise derivative · Employee Stock Option (right to buy) 8,000 $2.60 $20.8K
Filing: Form 4 (Insider Transaction) Insider: Bonvini Ezio (Sr VP, Research & CSO) Shares: 8,000
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-08-20

MGNX insider Peters Jeffrey Stuart (Senior VP, GC, and Secretary) sold 31,105 shares (~$129.1K)

Peters Jeffrey Stuart, listed as Senior VP, GC, and Secretary at MACROGENICS INC, reported an open-market sale of 31,105 MGNX shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
S Open-market sale 31,105 $4.15 $129.1K
Filing: Form 4 (Insider Transaction) Insider: Peters Jeffrey Stuart (Senior VP, GC, and Secretary) Shares: 31,105 Est. Value: $129.1K
View on SEC EDGAR → Open Filing Document →
Form 4 Option exercise Tax / Compensation Filing 2026-08-18

MGNX insider Form 4 filed for equity award, exercise, or tax withholding

Bonvini Ezio (Sr VP, Research & CSO) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

The insider converted options into shares. The exercise price was fixed when the options were granted, so the timing usually tracks an expiry schedule.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 40,000 $2.60 $104.0K
M Option exercise derivative · Employee Stock Option (right to buy) 40,000 $2.60 $104.0K
Filing: Form 4 (Insider Transaction) Insider: Bonvini Ezio (Sr VP, Research & CSO) Shares: 40,000
View on SEC EDGAR → Open Filing Document →
Form 4 Compensation award Tax / Compensation Filing 2026-05-20

MGNX insider Form 4 filed for equity award, exercise, or tax withholding

O'Brien Federica F. (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 3,750 — —
M Option exercise derivative · Restricted Stock Unit 3,750 — —
A Compensation award derivative · Stock Option (right to buy) 22,000 — —
A Compensation award derivative · Restricted Stock Unit 3,750 — —
Filing: Form 4 (Insider Transaction) Insider: O'Brien Federica F. (Director) Shares: 3,750
View on SEC EDGAR → Open Filing Document →
Form 4 Compensation award Tax / Compensation Filing 2026-05-20

MGNX insider Form 4 filed for equity award, exercise, or tax withholding

Jackson Scott Thomas (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 3,750 — —
M Option exercise derivative · Restricted Stock Unit 3,750 — —
A Compensation award derivative · Restricted Stock Unit 3,750 — —
A Compensation award derivative · Stock Option (right to buy) 22,000 — —
Filing: Form 4 (Insider Transaction) Insider: Jackson Scott Thomas (Director) Shares: 3,750
View on SEC EDGAR → Open Filing Document →
Form 4 Compensation award Tax / Compensation Filing 2026-05-20

MGNX insider Form 4 filed for equity award, exercise, or tax withholding

HEIDEN WILLIAM K (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 3,750 — —
M Option exercise derivative · Restricted Stock Unit 3,750 — —
A Compensation award derivative · Restricted Stock Unit 3,750 — —
A Compensation award derivative · Stock Option (right to buy) 22,000 — —
Filing: Form 4 (Insider Transaction) Insider: HEIDEN WILLIAM K (Director) Shares: 3,750
View on SEC EDGAR → Open Filing Document →
Form 4 Option exercise Tax / Compensation Filing 2026-05-20

MGNX insider Form 4 filed for equity award, exercise, or tax withholding

SIEGEL JAY PHILIP (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

The insider converted options into shares. The exercise price was fixed when the options were granted, so the timing usually tracks an expiry schedule.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 3,750 — —
M Option exercise derivative · Restricted Stock Unit 3,750 — —
Filing: Form 4 (Insider Transaction) Insider: SIEGEL JAY PHILIP (Director) Shares: 3,750
View on SEC EDGAR → Open Filing Document →
Form 4 Compensation award Tax / Compensation Filing 2026-05-20

MGNX insider Form 4 filed for equity award, exercise, or tax withholding

Liu Margaret (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 3,750 — —
M Option exercise derivative · Restricted Stock Unit 3,750 — —
A Compensation award derivative · Restricted Stock Unit 3,750 — —
A Compensation award derivative · Stock Option (right to buy) 22,000 — —
Filing: Form 4 (Insider Transaction) Insider: Liu Margaret (Director) Shares: 3,750
View on SEC EDGAR → Open Filing Document →
Form 4 Compensation award Tax / Compensation Filing 2026-05-20

MGNX insider Form 4 filed for equity award, exercise, or tax withholding

Chhabra Meenu (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 3,750 — —
A Compensation award derivative · Stock Option (right to buy) 22,000 — —
A Compensation award derivative · Restricted Stock Unit 3,750 — —
M Option exercise derivative · Restricted Stock Unit 3,750 — —
Filing: Form 4 (Insider Transaction) Insider: Chhabra Meenu (Director) Shares: 3,750
View on SEC EDGAR → Open Filing Document →
Proposed Insider Sales 5 · Form 144

A Form 144 is a notice of intent to sell restricted or control securities. It is not a record that anything was sold. MacroGenics, Inc. has 5 such notices in this period.

The distinction matters because a Form 144 is frequently reported as though it were a completed insider sale. The filer may sell all of the shares covered, some of them, or none at all, and there is no obligation to update the notice either way. A sale that is actually executed by an officer or director shows up separately on a Form 4, which is the filing to check before treating a proposed sale as a real one.

Form 144 Proposed Insider Sale 2026-09-21

MGNX Form 144 filed for proposed insider sale by Thomas Spitznagel (15,811 shares) ~$65.5K

Thomas Spitznagel filed a Form 144 with the SEC indicating intent to sell MGNX (MACROGENICS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Thomas Spitznagel Shares: 15,811 Est. Value: $65.5K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-08-19

MGNX Form 144 filed for proposed insider sale by Jeffrey Peters (31,105 shares) ~$129.1K

Jeffrey Peters filed a Form 144 with the SEC indicating intent to sell MGNX (MACROGENICS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Jeffrey Peters Shares: 31,105 Est. Value: $129.1K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-08-17

MGNX Form 144 filed for proposed insider sale by Jay Siegel (42,080 shares) ~$175.7K

Jay Siegel filed a Form 144 with the SEC indicating intent to sell MGNX (MACROGENICS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Jay Siegel Shares: 42,080 Est. Value: $175.7K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-08-03

MGNX Form 144 filed for proposed insider sale by Jay Siegel (34,916 shares) ~$130.9K

Jay Siegel filed a Form 144 with the SEC indicating intent to sell MGNX (MACROGENICS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Jay Siegel Shares: 34,916 Est. Value: $130.9K
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-07-13

MGNX Form 144 filed for proposed insider sale by Thomas Spitznagel (17,000 shares) ~$75.5K

Thomas Spitznagel filed a Form 144 with the SEC indicating intent to sell MGNX (MACROGENICS INC) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Thomas Spitznagel Shares: 17,000 Est. Value: $75.5K
View on SEC EDGAR → Open Filing Document →
Material Events 5 · Form 8-K

An 8-K reports a material event in the window between scheduled reports. There are 5 in this period for MacroGenics, Inc. Each 8-K names the item number it is filed under, and that number is the fastest way to tell a routine disclosure from a consequential one.

Item 2.02 is an earnings release, Item 5.02 is a change of directors or officers, and Item 1.01 or 2.01 covers a material agreement or a completed acquisition. Item 7.01 and Item 8.01 are the general-purpose disclosure items and carry no fixed meaning on their own.

Form 8-K/A Amended Material Company Update 2026-09-03

MGNX filed amended 8-K — material company event

MACROGENICS INC filed an amended 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K/A (Material Event Amendment)
View on SEC EDGAR → Open Filing Document →
Form 8-K Material Company Update 2026-08-13

MGNX filed 8-K — material company event

MACROGENICS INC filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)
View on SEC EDGAR → Open Filing Document →
Form 8-K Material Company Update 2026-07-23

MGNX filed 8-K — material company event

MACROGENICS INC filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)
View on SEC EDGAR → Open Filing Document →
Form 8-K Material Company Update 2026-07-08

MGNX filed 8-K — material company event

MACROGENICS INC filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)
View on SEC EDGAR → Open Filing Document →
Form 8-K Material Company Update 2026-07-07

MGNX filed 8-K — material company event

MACROGENICS INC filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)
View on SEC EDGAR → Open Filing Document →
Periodic Reports 1 · Forms 10-K and 10-Q

The periodic reports are where the audited and reviewed financial statements live. This period contains 1 quarterly report (10-Q) for MacroGenics, Inc.

The two are not equivalent in weight. A 10-K is audited by an external firm and includes the full risk factor disclosure, business description and management discussion; a 10-Q is unaudited, reviewed rather than examined, and much shorter. When a figure in a quarterly report is later revised, the annual report is usually where the correction appears.

An amended report — 10-K/A or 10-Q/A — restates or corrects something in the original filing, and is worth reading against the version it replaces.

Form 10-Q Quarterly Report 2026-08-14

MGNX filed Quarterly Report (10-Q)

MACROGENICS INC filed its quarterly report with the SEC. This report includes unaudited financial statements and management discussion for the quarter.

Filing: 10-Q (Quarterly Report)
View on SEC EDGAR → Open Filing Document →

How we classify MacroGenics, Inc.'s filings

Straight from EDGAR

Each displayed record links to an original source document. StrongBuyAnalytics provides navigation and brief excerpts or summaries, not the filing itself. Parsing may omit context or contain errors, so read the original document in full.

Transaction codes, not guesswork

The nature shown on each insider filing comes from the transaction code the filer entered on the form itself — P for an open-market purchase, A for a compensation award, F for shares withheld to pay tax, M for an option exercise. Where one filing contains several codes, the transaction table lists them line by line.

Why the distinction matters

Insider activity is routinely summarised as buying or selling, which flattens together decisions that mean very different things. Shares withheld for tax on a vesting grant are an automatic administrative step; shares bought on the open market are someone committing their own money at the current price.

What this page does not tell you

A filing records what happened, not why. Form 4 does not always disclose whether a sale was executed under a pre-arranged Rule 10b5-1 plan, and no single filing is a basis for a decision on MGNX. Read these alongside the fundamentals rather than in isolation.

Frequently Asked Questions — MGNX SEC Filings

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Publisher, sources & limitations — September 15, 2026. StrongBuyAnalytics provides navigation and brief excerpts or summaries for educational use. Original filings remain at SEC EDGAR or other displayed source links; StrongBuyAnalytics does not author them. Filing dates are source dates, not publication dates for this page. Coverage can be delayed, incomplete, amended, or unavailable because of SEC/source availability, parsing, caching, or outages. Verify every material statement in the original filing.
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