WEREWOLF THERAPEUTICS INC HOWL
COM · Common Stock · CUSIP 95075A107
- SectorHealth care
- IndustryPharmaceutical Preparations
- HeadquartersWaltham, MA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($57 this quarter). Holder counts are more reliable. Shares outstanding: 48.5m as of 2025-10-29, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $1.97. Options: 1 managers hold calls ($394 notional), 1 hold puts ($1.6k).
Trends to Q3 2025
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 45 |
| Q4 2022 | 40 |
| Q1 2023 | 39 |
| Q2 2023 | 37 |
| Q3 2023 | 36 |
| Q4 2023 | 42 |
| Q1 2024 | 62 |
| Q2 2024 | 72 |
| Q3 2024 | 70 |
| Q4 2024 | 74 |
| Q1 2025 | 71 |
| Q2 2025 | 66 |
| Q3 2025 | 62 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q4 2023 | 23 | 10 |
| Q1 2024 | 40 | 16 |
| Q2 2024 | 44 | 27 |
| Q3 2024 | 37 | 27 |
| Q4 2024 | 40 | 22 |
| Q1 2025 | 30 | 27 |
| Q2 2025 | 31 | 41 |
| Q3 2025 | 18 | 31 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q4 2024 | $42.7k | $39.7k | 0.93 |
| Q1 2025 | $6.9k | $25.4k | 3.69 |
| Q2 2025 | $1.3k | $9.0k | 6.87 |
| Q3 2025 | $394 | $1.6k | 4.00 |
Biggest buyers
| CITADEL ADVISORS LLC | New | +154.5k |
| RENAISSANCE TECHNOLOGIES LLC | Added | +139.7k |
| VANGUARD GROUP INC | Added | +109.8k |
| Cubist Systematic Strategies, LLC | New | +46.7k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | +13.4k |
| Virtu Financial LLC | New | +12.2k |
| Cetera Investment Advisers | New | +10.2k |
| UBS Group AG | Added | +9.3k |
| SIMPLEX TRADING, LLC | Added | +8.6k |
| CITIGROUP INC | Added | +8.3k |
Biggest sellers
| MILLENNIUM MANAGEMENT LLC | Reduced | -379.6k |
| BANK OF AMERICA CORP /DE/ | Reduced | -298.7k |
| BlackRock, Inc. | Reduced | -260.7k |
| GOLDMAN SACHS GROUP INC | Reduced | -167.1k |
| JANE STREET GROUP, LLC | Reduced | -106.4k |
| MARSHALL WACE, LLP | Sold out | -103.8k |
| Y-Intercept (Hong Kong) Ltd | Sold out | -84.4k |
| AQR CAPITAL MANAGEMENT LLC | Reduced | -74.4k |
| ACADIAN ASSET MANAGEMENT LLC | Reduced | -27.0k |
| Jain Global LLC | Sold out | -27.0k |
Biggest calls
| GROUP ONE TRADING LLC | Reduced | $394200 shares |
Biggest puts
| GROUP ONE TRADING LLC | Reduced | $1.6k800 shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| MOLL PETER 13G · exempt (held before listing) new · filed 2026-09-21 | 5.2% |
Fell to 5% or below in the last year: RA CAPITAL MANAGEMENT, L.P. (4.1%, 2026-07-02), MPM BioVentures 2014, L.P. (3.8%, 2026-05-12), Longwood Fund III, L.P. (3.5%, 2026-02-11)
Insider purchases and sales in Q3 2025
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2023 | 0 | — | 0 | — | — |
| Q1 2024 | 0 | — | 0 | — | — |
| Q2 2024 | 0 | — | 0 | — | — |
| Q3 2024 | 0 | — | 0 | — | — |
| Q4 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 1 | $2.5k | — |
| Q2 2025 | 1 | $487.2k | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
None reported in Q3 2025.
Holders, Q3 2025
| Manager | Shares | Change |
|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. 0.16% of their portfolio | 6.7m $13.2m | Unchanged |
| MPM ASSET MANAGEMENT LLC 19.08% of their portfolio | 4.3m $8.5m | Unchanged |
| MPM BIOIMPACT LLC 0.78% of their portfolio | 2.4m $4.7m | Unchanged |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 1.8m $3.6m | Reduced -298.7k |
| VANGUARD GROUP INC 0.00% of their portfolio | 1.4m $2.8m | Added +109.8k |
| SPHERA FUNDS MANAGEMENT LTD. 0.29% of their portfolio | 626.8k $1.2m | Unchanged |
| DC Funds, LP 37.32% of their portfolio | 589.1k $1.2m | Unchanged |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 456.0k $898.3k | Added +139.7k |
| PFM Health Sciences, LP 0.07% of their portfolio | 401.1k $790.2k | Unchanged |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 330.8k $651.8k | Added +2.8k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 317.1k $624.6k | Reduced -379.6k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 268.6k $529.1k | Reduced -106.4k |
| Alyeska Investment Group, L.P. 0.00% of their portfolio | 235.7k $464.3k | Unchanged |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 154.5k $304.4k | New |
| STATE STREET CORP 0.00% of their portfolio | 119.2k $234.8k | Unchanged |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 102.0k $200.9k | Unchanged |
| BlackRock, Inc. 0.00% of their portfolio | 101.3k $199.6k | Reduced -260.7k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 93.0k $183.3k | Added +13.4k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 65.8k $129.7k | Unchanged |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 60.3k $118.9k | Reduced -167.1k |
| EDGEWOOD MANAGEMENT LLC 0.00% of their portfolio | 50.0k $98.5k | Unchanged |
| Cubist Systematic Strategies, LLC 0.00% of their portfolio | 46.7k $92.0k | New |
| HRT FINANCIAL LP 0.00% of their portfolio | 39.9k $78.0k | Reduced -2.6k |
| Vontobel Holding Ltd. 0.00% of their portfolio | 36.0k $70.9k | Reduced -4.0k |
| TWO SIGMA ADVISERS, LP 0.00% of their portfolio | 34.6k $68.2k | Reduced -22.0k |
| ACADIAN ASSET MANAGEMENT LLC 0.00% of their portfolio | 34.3k $67.0k | Reduced -27.0k |
| Qube Research & Technologies Ltd 0.00% of their portfolio | 29.2k $57.6k | Reduced -15.0k |
| Regal Investment Advisors LLC 0.00% of their portfolio | 27.2k $53.6k | Unchanged |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 20.1k $39.7k | Reduced -25.3k |
| MORGAN STANLEY 0.00% of their portfolio | 19.3k $37.9k | Reduced -7.9k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 17.8k $35.1k | Reduced -74.4k |
| SIMPLEX TRADING, LLC 0.00% of their portfolio | 15.6k $30.0k | Added +8.6k |
| CERTUITY, LLC 0.00% of their portfolio | 15.0k $29.6k | Unchanged |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 14.4k $28.4k | Added +1.4k |
| BARCLAYS PLC 0.00% of their portfolio | 13.3k $26.2k | Added +39 |
| HBK Sorce Advisory LLC 0.00% of their portfolio | 13.2k $23.3k | Unchanged |
| Point72 Asia (Singapore) Pte. Ltd. 0.00% of their portfolio | 13.0k $25.6k | Reduced -7.1k |
| UBS Group AG 0.00% of their portfolio | 12.8k $25.2k | Added +9.3k |
| Virtu Financial LLC 0.00% of their portfolio | 12.2k $24.0k | New |
| FMR LLC 0.00% of their portfolio | 11.3k $22.2k | Unchanged |
| Cetera Investment Advisers 0.00% of their portfolio | 10.2k $20.1k | New |
| Larson Financial Group LLC 0.00% of their portfolio | 10.0k $19.7k | Unchanged |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 9.6k $13.3k | Unchanged |
| CITIGROUP INC 0.00% of their portfolio | 8.7k $17.1k | Added +8.3k |
| Financial Perspectives, Inc 0.00% of their portfolio | 6.8k $13.3k | Unchanged |
| Tower Research Capital LLC (TRC) 0.00% of their portfolio | 6.0k $11.8k | Reduced -8.4k |
| HIGHLINE WEALTH PARTNERS LLC 0.00% of their portfolio | 5.0k $9.8k | Reduced -5.0k |
| FEDERATED HERMES, INC. 0.00% of their portfolio | 4.4k $8.6k | Unchanged |
| GROUP ONE TRADING LLC 0.00% of their portfolio | 2.7k $5.3k | New |
| TFC Financial Management, Inc. 0.00% of their portfolio | 2.5k $4.9k | Unchanged |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 2.2k $4.4k | Reduced -8.7k |
| CWM, LLC 0.00% of their portfolio | 1.6k $3.0k | Reduced -6.9k |
| NISA INVESTMENT ADVISORS, LLC 0.00% of their portfolio | 1.4k $2.7k | Unchanged |
| Rossby Financial, LCC 0.00% of their portfolio | 860 $1.7k | Unchanged |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 806 $1.0k | Reduced -20.3k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 793 $1.6k | Reduced -2.8k |
| Advisory Services Network, LLC 0.00% of their portfolio | 157 $309 | New |
| Arax Advisory Partners 0.00% of their portfolio | 68 $133 | New |
| Plante Moran Financial Advisors, LLC 0.00% of their portfolio | 50 $99 | Unchanged |
| SBI Securities Co., Ltd. 0.00% of their portfolio | 41 $81 | Added +1 |
| EverSource Wealth Advisors, LLC 0.00% of their portfolio | 35 $69 | Reduced -132 |
| Optiver Holding B.V. 0.00% of their portfolio | 22 $43 | New |