Werewolf director-linked entities sell 157K HOWL shares

Werewolf Therapeutics director Luke Evnin reported that affiliated investment entities sold 157,084 shares of Werewolf Therapeutics common stock in an open-market transaction at a weighted average price of $0.30 per share.

Rhea-AI Filing Summary

Werewolf Therapeutics director Luke Evnin reported that affiliated investment entities sold 157,084 shares of Werewolf Therapeutics common stock in an open-market transaction at a weighted average price of $0.30 per share. The sales were executed on behalf of several MPM-managed entities under a Rule 10b5-1 trading plan dated March 26, 2026. Following the transactions, these entities together held 143,199 shares indirectly associated with Evnin, and he disclaims beneficial ownership of the securities except to the extent of his pecuniary interest.

Insider Trade Summary 10b5-1

Net Seller: 157,084 shares

Net Sell 1 txn

Insider EVNIN LUKE

Role Director

Sold 157,084 shs ($47K)

Type	Security	Shares	Price	Value
Sale	Common Stock	157,084	$0.30	$47K

Holdings After Transaction: Common Stock — 143,199 shares (Indirect, See Footnotes)

Footnotes (5)

1. F1. Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 dated March 26, 2026.
2. F2. The shares were sold as follows: 16,830 by MPM Asset Management LLC ("AM LLC"), 106,262 by MPM BioVentures 2014, L.P. ("BV 2014"), 7,087 by MPM BIoVentures 2014(B), L.P. ("BV 2014(B)"), 3,657 by MPM Asset Management Investors BV2014 LLC ("AM BV2014") and 23,248 by MPM Oncology Innovations Fund, L.P. ("MPM OIF").
3. F3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.2703 to $0.33 inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote.
4. F4. MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B). BV LLC is the manager of AM BV2014. MPM Oncology Innovations Fund GP LLC ("MPM OIF GP") is the general partner of MPM OIF. Luke Evnin is a member of AM LLC, a Managing Director of BV LLC and a manager of MPM OIF GP. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein.
5. F5. The shares are held as follows: 15,341 by AM LLC, 96,873 by BV 2014, 6,459 by BV 2014(B), 3,332 by AM BV2014 and 21,194 by MPM OIF.

Key Figures

Shares sold: 157,084 shares Weighted average sale price: $0.30 per share Shares held after transaction: 143,199 shares +5 more

8 metrics

Shares sold 157,084 shares Open-market sale on 2026-06-29

Weighted average sale price $0.30 per share Common stock sale

Shares held after transaction 143,199 shares Indirect holdings after sale

Price range of sales $0.2703–$0.33 per share Multiple transactions within this range

Shares sold by MPM BioVentures 2014, L.P. 106,262 shares Portion of total 157,084 shares sold

Shares held by MPM BioVentures 2014, L.P. 96,873 shares Indirect holdings after sale

Shares sold by MPM Oncology Innovations Fund, L.P. 23,248 shares Part of reported sale

Shares held by MPM Oncology Innovations Fund, L.P. 21,194 shares Indirect holdings after sale

Key Terms

Rule 10b5-1, weighted average price, pecuniary interest, beneficial ownership, +1 more

5 terms

Rule 10b5-1 regulatory

"Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 dated March 26, 2026."

Rule 10b5-1 is a regulation that allows company insiders to buy or sell their shares at predetermined times, even if they have access to non-public information. It acts like setting a schedule in advance for transactions, helping prevent accusations of unfair trading. This rule provides a way for insiders to plan trades transparently, giving investors confidence that these transactions are not based on hidden information.

weighted average price financial

"The price reported in Column 4 is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

pecuniary interest financial

"The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein."

beneficial ownership financial

"The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein."

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.

open-market sale financial

"transaction_action": "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

FAQ

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

What insider transaction did HOWL director Luke Evnin report?

Luke Evnin reported that affiliated investment entities sold 157,084 shares of Werewolf Therapeutics common stock. The transaction was an open-market sale, with a weighted average price of $0.30 per share, and reflects activity by MPM-managed entities associated with him.

At what price were the Werewolf Therapeutics (HOWL) shares sold?

The reported price is a weighted average of $0.30 per share. According to the filing, multiple trades occurred within a price range from $0.2703 to $0.33 per share, resulting in the disclosed weighted average sale price.

Were the HOWL insider sales by Luke Evnin pre-planned?

Yes. The filing states the transaction was effected under a Rule 10b5-1 trading plan dated March 26, 2026. Such plans pre-schedule trades, indicating the timing of these sales was established in advance rather than decided on the trade date.

Which entities actually sold the Werewolf Therapeutics (HOWL) shares?

The shares were sold by MPM Asset Management LLC, MPM BioVentures 2014, L.P., MPM BioVentures 2014(B), L.P., MPM Asset Management Investors BV2014 LLC, and MPM Oncology Innovations Fund, L.P. These entities are associated with Luke Evnin through various general partner and manager roles.

How many HOWL shares remain held by entities associated with Luke Evnin?

After the reported sales, entities associated with Luke Evnin held 143,199 shares of Werewolf Therapeutics common stock. These are spread across the same MPM-related entities, and Evnin disclaims beneficial ownership except for his pecuniary interest in those holdings.

Does Luke Evnin claim full beneficial ownership of the HOWL shares?

No. The filing explains that Luke Evnin is affiliated with the MPM entities that hold the shares but disclaims beneficial ownership of the securities, except to the extent of his pecuniary interest. This clarifies that the positions are held primarily at the entity level.

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

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Accepted by SEC EDGAR 06/29/2026 - 07:07 PM Learn about SEC filing dates

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).

X

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^*

EVNIN LUKE

(Last) (First) (Middle)

C/O MPM BIOIMPACT LLC

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Werewolf Therapeutics, Inc. [ HOWL ]

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/29/2026

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

X	Form filed by One Reporting Person
	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	06/29/2026		S(1)		157,084(2)	D	$0.3(3)	143,199	I	See Footnotes(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

Explanation of Responses:

1. Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 dated March 26, 2026.

2. The shares were sold as follows: 16,830 by MPM Asset Management LLC ("AM LLC"), 106,262 by MPM BioVentures 2014, L.P. ("BV 2014"), 7,087 by MPM BIoVentures 2014(B), L.P. ("BV 2014(B)"), 3,657 by MPM Asset Management Investors BV2014 LLC ("AM BV2014") and 23,248 by MPM Oncology Innovations Fund, L.P. ("MPM OIF").

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.2703 to $0.33 inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote.

4. MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B). BV LLC is the manager of AM BV2014. MPM Oncology Innovations Fund GP LLC ("MPM OIF GP") is the general partner of MPM OIF. Luke Evnin is a member of AM LLC, a Managing Director of BV LLC and a manager of MPM OIF GP. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein.

5. The shares are held as follows: 15,341 by AM LLC, 96,873 by BV 2014, 6,459 by BV 2014(B), 3,332 by AM BV2014 and 21,194 by MPM OIF.

	/s/ Luke Evnin	06/29/2026
	** 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)