[Form 4] Lantheus Holdings, Inc Insider Trading Activity

Rhea-AI Filing Summary

Insiders from Farallon-affiliated funds reported large open-market dispositions of Lantheus Holdings (LNTH) stock on August 19-20, 2025. The filing shows a sale of 41,000 shares on 08/19/2025 at $55.34 and a weighted-average sale of 3,365,000 shares on 08/20/2025 at $56.15. The reported beneficial ownership for the group fell from 6,842,227 shares after the first sale to 3,477,227 shares after the second sale. Footnotes identify the sellers as Farallon Funds and multiple managing members who disclaim beneficial ownership except for any pecuniary interest. The Form 4s were signed by an attorney-in-fact on 08/21/2025.

Positive

• None.

Negative

• Large open-market dispositions: 3,365,000 shares sold on 08/20/2025 (weighted-average $56.15) and 41,000 shares sold on 08/19/2025 ($55.34).
• Significant reduction in reported stake: Beneficial ownership decreased from 6,842,227 shares to 3,477,227 shares after reported transactions.
• Grouped selling by Farallon-affiliated parties: Footnotes indicate coordinated reporting persons and parallel Form 4s, which may signal a material change in holdings by the group.

Insights

Financial Analyst

TL;DR: Large, concentrated sales by Farallon-affiliated reporting persons materially reduce their reported stake in LNTH.

The transactions disclose a substantial reduction in reported beneficial ownership: a 41,000-share sale followed by a 3,365,000-share sale using a weighted-average price of $56.15. Proceeds from the 08/20/2025 sale approximate $189 million, with the prior 08/19/2025 sale adding roughly $2.3 million. Such large open-market dispositions by an activist/hedge-fund-affiliated group are material for investors because they significantly lower the group's reported stake and may affect market supply and perceived insider sentiment. Filings reference additional parallel Form 4s and disclaimers regarding beneficial ownership through Farallon structures.

Corporate Governance Expert

TL;DR: Multiple managing members and general partner entities are disclosed, with standard disclaimers and parallel filings noted.

The Form 4 details that the shares are held directly by Farallon-affiliated funds and that Farallon General Partners and individual Managing Members may be deemed to have investment discretion. The footnotes emphasize disclaimers of beneficial ownership except for pecuniary interest and indicate parallel Form 4s filed for additional reporting persons. From a governance perspective, the disclosure is thorough but highlights a coordinated group reduction of holdings that stakeholders may interpret as a change in insider alignment.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

PATEL RAJIV A

(Last) (First) (Middle)

C/O FARALLON CAPITAL MANAGEMENT, L.L.C.

ONE MARITIME PLAZA, SUITE 2100

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Lantheus Holdings, Inc. [ LNTH ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of a Group Owning 10%

3. Date of Earliest Transaction (Month/Day/Year)
08/19/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/19/2025		S		41,000	D	$55.34	6,842,227	I	See Footnotes(1)(2)(3)(4)(5)
Common Stock	08/20/2025		S		3,365,000	D	$56.15(6)	3,477,227	I	See Footnotes(1)(2)(3)(4)(5)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person^*

PATEL RAJIV A

(Last) (First) (Middle)

C/O FARALLON CAPITAL MANAGEMENT, L.L.C.

ONE MARITIME PLAZA, SUITE 2100

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of a Group Owning 10%

1. Name and Address of Reporting Person^*

Roberts Thomas G. Jr.

(Last) (First) (Middle)

C/O FARALLON CAPITAL MANAGEMENT, L.L.C.

ONE MARITIME PLAZA, SUITE 2100

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of a Group Owning 10%

1. Name and Address of Reporting Person^*

Saito Edric C.

(Last) (First) (Middle)

C/O FARALLON CAPITAL MANAGEMENT, L.L.C.

ONE MARITIME PLAZA, SUITE 2100

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of a Group Owning 10%

1. Name and Address of Reporting Person^*

Seybold William

(Last) (First) (Middle)

C/O FARALLON CAPITAL MANAGEMENT, L.L.C.

ONE MARITIME PLAZA, SUITE 2100

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of a Group Owning 10%

1. Name and Address of Reporting Person^*

Short Daniel S.

(Last) (First) (Middle)

C/O FARALLON CAPITAL MANAGEMENT, L.L.C.

ONE MARITIME PLAZA, SUITE 2100

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of a Group Owning 10%

1. Name and Address of Reporting Person^*

Spokes Andrew J M

(Last) (First) (Middle)

C/O FARALLON CAPITAL MANAGEMENT, L.L.C.

ONE MARITIME PLAZA, SUITE 2100

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of a Group Owning 10%

1. Name and Address of Reporting Person^*

Warren John R.

(Last) (First) (Middle)

C/O FARALLON CAPITAL MANAGEMENT, L.L.C.

ONE MARITIME PLAZA, SUITE 2100

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of a Group Owning 10%

1. Name and Address of Reporting Person^*

WEHRLY MARK C

(Last) (First) (Middle)

C/O FARALLON CAPITAL MANAGEMENT, L.L.C.

ONE MARITIME PLAZA, SUITE 2100

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Member of a Group Owning 10%

Explanation of Responses:

1. The entities and individuals identified in the footnotes of this Form 4 may be deemed members of a group holding equity securities of Lantheus Holdings, Inc. (the "Issuer"). The filing of this Form 4 and any statements included herein shall not be deemed to be an admission that such entities and individuals are members of such a group.

2. Since the number of reporting persons that may be listed on a Form 4 is limited, the entities and individuals listed in these footnotes that are not reporting persons on this Form 4 are filing an additional Form 4 on the date hereof as reporting persons with respect to the securities described herein (the "Parallel Form 4"). Information regarding these entities and individuals is included in this Form 4 for purposes of clarification and convenience only, and is duplicative of the information reported in the Parallel Form 4.

3. The amount of securities shown in this row is held directly by certain investment funds affiliated with the reporting persons (the "Farallon Funds").

4. Farallon Partners, L.L.C. and certain affiliated entities (the "Farallon General Partners"), as general partner or sole member of the general partner, as the case may be, of each of the Farallon Funds, may be deemed to be a beneficial owner of the Issuer's securities held by the Farallon Funds. The Farallon General Partners disclaim any beneficial ownership of any of the Issuer's securities reported or noted herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended (the "'34 Act"), or otherwise, except to the extent of their pecuniary interest, if any.

5. Each of Joshua J. Dapice, Philip D. Dreyfuss, Hannah E. Dunn, Richard B. Fried, Varun N. Gehani, Nicolas Giauque, David T. Kim, Michael G. Linn, Patrick (Cheng) Luo, Rajiv A. Patel, Thomas G. Roberts, Jr., Edric C. Saito, William Seybold, Daniel S. Short, Andrew J. M. Spokes, John R. Warren, and Mark C. Wehrly (collectively, the "Managing Members"), as a managing member or manager, or senior managing member or senior manager, as the case may be, of each of the Farallon General Partners, in each case with the power to exercise investment discretion, may be deemed to be a beneficial owner of the Issuer's securities held by the Farallon Funds. Each of the Managing Members disclaims any beneficial ownership of any of the Issuer's securities reported or noted herein for purposes of Section 16 of the '34 Act or otherwise, except to the extent of his or her pecuniary interest, if any.

6. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $56.14 to $56.55, inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range.

	/s/ Hannah E. Dunn, as attorney-in-fact	08/21/2025
	/s/ Hannah E. Dunn, as attorney-in-fact	08/21/2025
	/s/ Hannah E. Dunn, as attorney-in-fact	08/21/2025
	/s/ Hannah E. Dunn, as attorney-in-fact	08/21/2025
	/s/ Hannah E. Dunn, as attorney-in-fact	08/21/2025
	/s/ Hannah E. Dunn, as attorney-in-fact	08/21/2025
	/s/ Hannah E. Dunn, as attorney-in-fact	08/21/2025
	/s/ Hannah E. Dunn, as attorney-in-fact	08/21/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transactions were reported for Lantheus Holdings (LNTH)?

The filing reports a sale of 41,000 shares on 08/19/2025 at $55.34 and a sale of 3,365,000 shares on 08/20/2025 at a weighted-average price of $56.15.

How did the reported beneficial ownership change after the transactions?

Reported beneficial ownership fell from 6,842,227 shares after the 08/19 sale to 3,477,227 shares after the 08/20 sale.

Who are the reporting persons in this Form 4 filing?

The reporting persons are members and managers associated with Farallon-affiliated funds, including multiple Managing Members and Farallon General Partners, with filings signed by an attorney-in-fact.

Are there disclaimers or additional filings noted?

Yes. Footnotes state that parallel Form 4s are filed for additional entities and that General Partners and Managing Members disclaim beneficial ownership except for any pecuniary interest.

When were the Form 4 signatures executed?

The Forms were signed by Hannah E. Dunn, as attorney-in-fact, on 08/21/2025.