Steven Ratner plans $219K Mercury Systems sale

MERCURY SYSTEMS INC (MRCY) is the issuer for which Steven V. Ratner has filed a Rule 144 notice covering planned sales of common stock.

Rhea-AI Filing Summary

MERCURY SYSTEMS INC (MRCY) is the issuer for which Steven V. Ratner has filed a Rule 144 notice covering planned sales of common stock. The notice lists 1,971 shares of common stock proposed to be sold through Fidelity Brokerage Services LLC, with an aggregate market value of $219,486.03, and indicates these shares relate to restricted stock that vested on 08/17/2026. The filing also reports that Ratner sold 1,084 shares of common stock during the prior three months for total proceeds of $119,186.78, with a remark that part of the sale is intended to cover tax obligations from a vested equity award distribution.

Key Figures

Shares to be sold: 1,971 shares Aggregate market value of shares to be sold: $219,486.03 Shares sold in past 3 months: 1,084 shares +3 more

6 metrics

Shares to be sold 1,971 shares Common stock proposed to be sold under Rule 144

Aggregate market value of shares to be sold $219,486.03 Estimated market value of 1,971 MRCY shares covered by the notice

Shares sold in past 3 months 1,084 shares MRCY common stock sold by Steven V. Ratner on 08/17/2026

Proceeds from past 3-month sale $119,186.78 Total consideration for 1,084 MRCY shares sold on 08/17/2026

Notice date 08/18/2026 Date of Rule 144 notice for proposed MRCY share sale

Issuer phone 9782561300 Contact phone number for MERCURY SYSTEMS INC

Key Terms

Rule 144, Restricted Stock Vesting, attorney-in-fact, aggregate market value

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Restricted Stock Vesting financial

"Common | 08/17/2026 | Restricted Stock Vesting | Issuer"

Restricted stock vesting is the timetable and conditions under which shares granted to employees or insiders become fully owned and can be sold, typically requiring continued work or meeting performance goals. It matters to investors because large blocks of shares can become tradable at once, which can change share supply and price, and because vesting aligns insiders’ incentives with the company’s long‑term performance—think of it like a timed unlock that both rewards and locks in key people.

attorney-in-fact regulatory

"as attorney-in-fact for Steven V. Ratner."

An attorney-in-fact is the person or entity given legal authority through a power of attorney to act on behalf of another for specific tasks, such as signing documents, voting shares, or handling transactions. For investors, this matters because it lets a trusted representative make timely decisions or complete paperwork when the owner cannot, much like handing keys to someone to run errands on your behalf—so checks on scope and limits of that authority are important.

aggregate market value financial

"1971 | 219486.03 | 60043283 | 08/18/2026 | NASDAQ"

Aggregate market value is the combined price you would pay to buy all outstanding shares of a company or all companies in a group at current market prices — essentially the sum of each stock’s market capitalization. It matters to investors because it shows the overall size and weight of an investment or sector (like the total cost to buy every piece of a puzzle), helps compare scale across companies or markets, and influences index composition and risk exposure.

FAQ

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

What does the Rule 144 filing mean for MERCURY SYSTEMS INC (MRCY)?

The filing discloses that Steven V. Ratner plans to sell 1,971 shares of MRCY common stock under Rule 144. This is a compliance notice for resales of restricted or control securities and does not involve the company issuing new shares.

How many MRCY shares are covered by Steven Ratner’s planned Rule 144 sale?

The notice covers 1,971 shares of MERCURY SYSTEMS INC common stock with an aggregate market value of $219,486.03. These shares are to be sold through Fidelity Brokerage Services LLC and are listed on NASDAQ.

What prior MRCY share sales did Steven Ratner report in this Rule 144 notice?

The notice reports that on 08/17/2026, Steven V. Ratner sold 1,084 MRCY common shares for total proceeds of $119,186.78. These sales occurred within the three months prior to the notice date and must be aggregated under Rule 144.

Why does the Rule 144 filing mention tax obligations for MRCY equity awards?

The remarks state the sale includes an amount to cover a tax obligation arising from settlement of a vested equity award distribution. This indicates part of the shares sold are associated with restricted stock vesting and related tax withholding needs.

Who is executing Steven Ratner’s planned MRCY stock sale under Rule 144?

The proposed sale is to be executed through Fidelity Brokerage Services LLC, located in Smithfield, RI. The Rule 144 notice is signed by Wade Moss, as a duly authorized representative of Fidelity and attorney-in-fact for Steven V. Ratner.

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

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Accepted by SEC EDGAR 08/18/2026 - 03:39 PM EDT 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	0001995110
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	MERCURY SYSTEMS INC
SEC File Number	001-41194
Address of Issuer	50 MINUTEMAN ROAD ANDOVER MASSACHUSETTS 01810
Phone	9782561300
Name of Person for Whose Account the Securities are To Be Sold	Ratner Steven
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	Officer

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	Fidelity Brokerage Services LLC 900 Salem Street Smithfield RI 02917	1971	219486.03	60043283	08/18/2026	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	Restricted Stock Vesting	Issuer			1971	08/17/2026	Compensation

* 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
Steven V. Ratner 50 MINUTEMAN ROAD ANDOVER MA 01810	Common	08/17/2026	1084	119186.78

144: Remarks and Signature

Remarks	Sale includes an amount necessary to cover a tax obligation resulting from the settlement of a vested equity award distribution.
Date of Notice	08/18/2026
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	/s/Wade Moss, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Steven V. Ratner.
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)