MacroGenics’ Jay Siegel plans sale of 42,080 shares

MacroGenics, Inc. (symbol MGNX) has a notice of proposed resale of its common stock under Form 144.

Rhea-AI Filing Summary

MacroGenics, Inc. (symbol MGNX) has a notice of proposed resale of its common stock under Form 144. The filing lists 42,080 shares of common stock to be sold through Merrill Lynch, with a proposed sale date of 08/17/2026 on NASDAQ.

The seller is identified as Jay Siegel, with a section also listing securities sold during the past 3 months: on 08/03/2026, a transaction in common stock for 34,916 shares is reported, alongside a related value of 130,905. Another numeric identifier 63,700,187 appears in the securities information section.

Key Figures

Proposed shares to be sold: 42,080 shares Proposed sale date: 08/17/2026 Shares sold during past 3 months: 34,916 shares +2 more

5 metrics

Proposed shares to be sold 42,080 shares Common stock listed with Merrill Lynch with proposed sale date 08/17/2026

Proposed sale date 08/17/2026 Date associated with 42,080 shares of common stock to be sold on NASDAQ

Shares sold during past 3 months 34,916 shares Common stock transaction dated 08/03/2026 in the past 3 months section

Related value for past sale 130,905 Figure reported alongside 34,916 shares sold on 08/03/2026

Security identifier 63,700,187 Numeric identifier shown in the securities information line for common stock

Key Terms

Form 144, Securities To Be Sold, Securities Sold During The Past 3 Months, stock plan activity

4 terms

Form 144 regulatory

"144: Filer Information | | | 144: Filer Information"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Securities To Be Sold financial

"144: Securities To Be Sold Common | 08/17/2026 | Stock plan activity"

Securities Sold During The Past 3 Months financial

"144: Securities Sold During The Past 3 Months Jay Siegel"

stock plan activity financial

"Common | 08/17/2026 | Stock plan activity | Issuer"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does MacroGenics (MGNX) report in this Form 144 filing?

MacroGenics (MGNX) reports a Form 144 notice for a proposed resale of 42,080 shares of its common stock. The shares are planned to be sold through Merrill Lynch on or after 08/17/2026 on NASDAQ.

How many MacroGenics (MGNX) shares are proposed to be sold under this Form 144?

The Form 144 indicates a proposed sale of 42,080 shares of MacroGenics common stock. These shares are listed under the securities information section with Merrill Lynch as broker and a proposed sale date of 08/17/2026.

Who is the reporting person in the MacroGenics (MGNX) Form 144?

The reporting person is Jay Siegel, with an address in Rockville, Maryland. His name appears in the section describing securities sold during the past 3 months, linked to prior sales of MacroGenics common stock.

What prior sales are disclosed in the MacroGenics (MGNX) Form 144?

The filing notes that on 08/03/2026, 34,916 shares of MacroGenics common stock were sold. This transaction is listed with a related figure of 130,905 in the “Securities Sold During The Past 3 Months” section.

On which market are the MacroGenics (MGNX) shares in this Form 144 expected to trade?

The shares in this Form 144 are associated with NASDAQ. The securities information section specifies NASDAQ as the market for the proposed sale of 42,080 shares of MacroGenics common stock.

Which broker is named in the MacroGenics (MGNX) Form 144 transaction?

The broker named is Merrill Lynch, with an address at 1800 K St NW, Suite 800, Washington, DC 20006. Merrill Lynch is listed in connection with the proposed sale of 42,080 shares of MacroGenics common stock.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/17/2026 - 05:37 PM Accepted by SEC EDGAR 08/17/2026 - 05:36 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001722857
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	MACROGENICS, INC.
SEC File Number
Address of Issuer	9704 Medical Center Drive Rockville MARYLAND 20850
Phone	3012515172
Name of Person for Whose Account the Securities are To Be Sold	Jay Siegel
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Former Director

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Merrill Lynch 1800 K St NW Suite 800 Washington DC 20006	42080	175695	63700187	08/17/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	08/17/2026	Stock plan activity	Issuer			42080	08/17/2026	n/a

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Jay Siegel 9704 Medical Center Drive Rockville MD 20850	Common	08/03/2026	34916	130905

144: Remarks and Signature

Remarks
Date of Notice	08/17/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	Jay Siegel
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)