Fairmount-linked fund boosts Viridian (VRDN) stake with 1.18M-share open-market buy

Rhea-AI Filing Summary

Viridian Therapeutics insider entities reported a large open-market share purchase. On May 11, 2026, Fairmount Healthcare Fund II L.P. bought 1,176,470 shares of Viridian common stock at $17.00 per share in an open-market transaction. After this trade, the fund’s indirect holdings reported in the filing totaled 5,090,928 shares.

Fairmount Funds Management LLC and Fairmount Healthcare Fund II GP LLC have voting and investment power over the shares held by Fairmount Healthcare Fund II L.P., but each disclaims beneficial ownership except to the extent of any pecuniary interest.

Insights

Equity ownership analyst

Fairmount-related fund disclosed a sizable open-market purchase in Viridian shares.

The filing shows Fairmount Healthcare Fund II L.P. acquiring 1,176,470 Viridian common shares at $17.00 per share on May 11, 2026. This is a straightforward open-market purchase, classified under transaction code P, rather than a derivative exercise or mechanistic adjustment.

Following the transaction, the fund’s indirect position reported in the filing stands at 5,090,928 shares. Two affiliated entities, Fairmount Funds Management LLC and Fairmount Healthcare Fund II GP LLC, hold voting and investment power, but each disclaims beneficial ownership beyond its pecuniary interest, which is a common structure for managed funds.

Insider Trade Summary

Net Buyer: 1,176,470 shares ($19,999,990)

Net Buy 1 txn

Insider Fairmount Funds Management LLC, Fairmount Healthcare Fund II GP LLC, Fairmount Healthcare Fund II L.P.

Role null | null | null

Bought 1,176,470 shs ($20.00M)

Type	Security	Shares	Price	Value
Purchase	Common Stock	1,176,470	$17.00	$20.00M

Holdings After Transaction: Common Stock — 5,090,928 shares (Indirect, By Fairmount Healthcare Fund II L.P.)

Footnotes (1)

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Key Figures

Shares purchased: 1,176,470 shares Purchase price: $17.00 per share Post-transaction holdings: 5,090,928 shares +2 more

5 metrics

Shares purchased 1,176,470 shares Open-market purchase on May 11, 2026

Purchase price $17.00 per share Common stock transaction code P

Post-transaction holdings 5,090,928 shares Indirect position of Fairmount Healthcare Fund II L.P.

Transaction code P (open-market purchase) Non-derivative common stock

Ownership type Indirect (I) Held by Fairmount Healthcare Fund II L.P.

Key Terms

open-market purchase, beneficial ownership, pecuniary interest, voting power and investment power, +1 more

5 terms

open-market purchase financial

"transaction_action": "open-market purchase""

An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.

beneficial ownership regulatory

"They disclaim beneficial ownership of securities held by Fund II"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

pecuniary interest financial

"except to the extent of their pecuniary interest therein"

voting power and investment power financial

"have voting power and investment power over the securities"

Rule 16a-1(a)(2) regulatory

"for purposes of Rule 16a-1(a)(2)"

Form 4 Insider Transactions: What Each Field Means →

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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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^*

Fairmount Funds Management LLC

(Last) (First) (Middle)

200 BARR HARBOR DRIVE

SUITE 400

(Street)

WEST CONSHOHOCKEN PENNSYLVANIA 19428

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Viridian Therapeutics, Inc.\DE [ VRDN ]

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

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/11/2026

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

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

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

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	05/11/2026		P		1,176,470	A	$17	5,090,928	I	By Fairmount Healthcare Fund II L.P.(1)

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^*

Fairmount Funds Management LLC

(Last) (First) (Middle)

200 BARR HARBOR DRIVE

SUITE 400

(Street)

WEST CONSHOHOCKEN PENNSYLVANIA 19428

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Fairmount Healthcare Fund II GP LLC

(Last) (First) (Middle)

200 BARR HARBOR DRIVE

SUITE 400

(Street)

WEST CONSHOHOCKEN PENNSYLVANIA 19428

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Fairmount Healthcare Fund II L.P.

(Last) (First) (Middle)

200 BARR HARBOR DRIVE

SUITE 400

(Street)

WEST CONSHOHOCKEN PENNSYLVANIA 19428

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. Fairmount Funds Management LLC ("Fairmount") and Fairmount Healthcare Fund II GP LLC ("Fairmount GP II") have voting power and investment power over the securities held by Fairmount Healthcare Fund II LP ("Fund II"). They disclaim beneficial ownership of securities held by Fund II for purposes of Rule 16a-1(a)(2), except to the extent of their pecuniary interest therein.

Remarks:

The Reporting Persons may each be deemed a director by deputization of Issuer by virtue of the fact that Tomas Kiselak serves on the board of directors of Issuer and is also a Managing Member of Fairmount Funds Management LLC.

	/s/ Peter Harwin, Managing Member of Fairmount Funds Management LLC	05/13/2026
	/s/ Peter Harwin, Managing Member of Fairmount Healthcare Fund II GP LLC	05/13/2026
	/s/ Peter Harwin, Managing Member of Fairmount Healthcare Fund II L.P.	05/13/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did Viridian Therapeutics (VRDN) disclose in this Form 4?

Viridian Therapeutics disclosed that Fairmount Healthcare Fund II L.P. purchased 1,176,470 shares of its common stock. The shares were acquired in an open-market transaction at $17.00 per share, reflecting a sizable increase in the fund’s reported indirect position in Viridian.

Who actually purchased the Viridian Therapeutics (VRDN) shares reported in the Form 4?

The purchaser was Fairmount Healthcare Fund II L.P., which now holds 5,090,928 Viridian shares indirectly. Fairmount Funds Management LLC and Fairmount Healthcare Fund II GP LLC have voting and investment power over these securities but disclaim beneficial ownership except for any pecuniary interest.

How many Viridian Therapeutics (VRDN) shares were bought and at what price?

Fairmount Healthcare Fund II L.P. bought 1,176,470 shares of Viridian Therapeutics common stock. The shares were acquired at a price of $17.00 per share in an open-market purchase dated May 11, 2026, according to the filed transaction details.

What is Fairmount Healthcare Fund II L.P.’s total Viridian (VRDN) position after this transaction?

After the reported purchase, Fairmount Healthcare Fund II L.P.’s indirect holdings in Viridian total 5,090,928 shares. This figure reflects the position following the 1,176,470-share open-market acquisition disclosed, providing a snapshot of the fund’s reported stake as of the transaction date.

Do Fairmount entities claim full beneficial ownership of the Viridian (VRDN) shares?

No. Fairmount Funds Management LLC and Fairmount Healthcare Fund II GP LLC have voting and investment power over shares held by Fairmount Healthcare Fund II L.P. However, they expressly disclaim beneficial ownership under Rule 16a-1(a)(2), except to the extent of any pecuniary interest they may have.