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. Holder counts are more reliable. Shares outstanding: 48.6m as of 2026-07-27, 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 ≈ $0.36. Options: 1 managers hold calls ($27.0k notional), 2 hold puts ($6.0k).
Trends to Q2 2026
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 |
| Q4 2025 | 51 |
| Q1 2026 | 48 |
| Q2 2026 | 45 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 37 | 27 |
| Q4 2024 | 40 | 22 |
| Q1 2025 | 30 | 27 |
| Q2 2025 | 31 | 41 |
| Q3 2025 | 18 | 31 |
| Q4 2025 | 20 | 33 |
| Q1 2026 | 16 | 24 |
| Q2 2026 | 18 | 21 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $394 | $1.6k | 4.00 |
| Q4 2025 | $0 | $0 | — |
| Q1 2026 | $0 | $0 | — |
| Q2 2026 | $27.0k | $6.0k | 0.22 |
Biggest buyers
| Balyasny Asset Management L.P. | New | +1.8m |
| Verdad Advisers, LP | Added | +318.9k |
| XTX Topco Ltd | Added | +220.5k |
| JANE STREET GROUP, LLC | Added | +169.0k |
| RENAISSANCE TECHNOLOGIES LLC | Added | +158.4k |
| UBS Group AG | Added | +149.0k |
| Squarepoint Ops LLC | New | +103.2k |
| Rangeley Capital, LLC | New | +100.0k |
| BANK OF AMERICA CORP /DE/ | Added | +46.9k |
| Virtu Financial LLC | New | +45.5k |
Biggest sellers
| RA CAPITAL MANAGEMENT, L.P. | Reduced | -4.3m |
| MPM BIOIMPACT LLC | Reduced | -1.1m |
| Squadron Capital Management LLC | Sold out | -563.5k |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | Sold out | -77.0k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -70.0k |
| GEODE CAPITAL MANAGEMENT, LLC | Reduced | -53.7k |
| SIMPLEX TRADING, LLC | Reduced | -32.3k |
| RAYMOND JAMES FINANCIAL INC | Sold out | -19.8k |
| GOLDMAN SACHS GROUP INC | Reduced | -18.2k |
| HRT FINANCIAL LP | Sold out | -17.9k |
Biggest calls
| CITADEL ADVISORS LLC | New | $27.0k75.0k shares |
Biggest puts
| CITADEL ADVISORS LLC | New | $5.6k15.5k shares |
| SIMPLEX TRADING, LLC | New | $3951.1k 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 since 1 Apr 2026
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 2024 | 0 | — | 0 | — | — |
| Q1 2025 | 0 | — | 1 | $2.5k | — |
| Q2 2025 | 1 | $487.2k | 0 | — | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 1 | $1.9m | $1.9m |
| Q1 2026 | 0 | — | 1 | $193.8k | $193.8k |
| Q2 2026 | 0 | — | 1 | $1.1m | $1.1m |
| Q3 2026 | 0 | — | 1 | $44.7k | $44.7k |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-07-07 | EVNIN LUKE Director · See Footnotes | Sold plan | $33.3k107.4k shares |
| 2026-07-06 | EVNIN LUKE Director · See Footnotes | Sold plan | $11.4k35.8k shares |
| 2026-06-29 | EVNIN LUKE Director · See Footnotes | Sold plan | $47.1k157.1k shares |
| 2026-06-17 | RA Capital Healthcare Fund LP +3 10% owner · See footnotes | Sold | $145.9k416.9k shares |
| 2026-06-16 | RA Capital Healthcare Fund LP +3 10% owner · See footnotes | Sold | $55.4k149.6k shares |
| 2026-06-15 | RA Capital Healthcare Fund LP +3 10% owner · See footnotes | Sold | $50.2k128.8k shares |
| 2026-06-12 | RA Capital Healthcare Fund LP +3 10% owner · See footnotes | Sold | $68.2k170.4k shares |
| 2026-06-11 | RA Capital Healthcare Fund LP +3 10% owner · See footnotes | Sold | $99.8k262.5k shares |
| 2026-06-10 | RA Capital Healthcare Fund LP +3 10% owner · See footnotes | Sold | $17.0k45.9k shares |
| 2026-06-09 | RA Capital Healthcare Fund LP +3 10% owner · See footnotes | Sold | $136.8k369.8k shares |
| 2026-06-09 | EVNIN LUKE Director · See Footnotes | Sold plan | $28.5k76.9k shares |
| 2026-06-08 | EVNIN LUKE Director · See Footnotes | Sold plan | $24.2k60.5k shares |
| 2026-06-05 | EVNIN LUKE Director · See Footnotes | Sold plan | $10.0k24.9k shares |
| 2026-06-04 | EVNIN LUKE Director · See Footnotes | Sold plan | $8.8k20.1k shares |
| 2026-06-03 | EVNIN LUKE Director · See Footnotes | Sold plan | $12.5k29.7k shares |
| 2026-06-02 | EVNIN LUKE Director · See Footnotes | Sold plan | $13.3k29.6k shares |
| 2026-06-01 | EVNIN LUKE Director · See Footnotes | Sold plan | $37.8k80.5k shares |
| 2026-05-29 | EVNIN LUKE Director · See Footnotes | Sold plan | $14.7k32.6k shares |
| 2026-05-28 | EVNIN LUKE Director · See Footnotes | Sold plan | $12.7k27.7k shares |
| 2026-05-27 | EVNIN LUKE Director · See Footnotes | Sold plan | $38.8k80.9k shares |
| 2026-05-26 | EVNIN LUKE Director · See Footnotes | Sold plan | $31.9k68.0k shares |
| 2026-05-22 | EVNIN LUKE Director · See Footnotes | Sold plan | $39.3k87.4k shares |
| 2026-05-21 | EVNIN LUKE Director · See Footnotes | Sold plan | $15.3k36.4k shares |
| 2026-05-20 | EVNIN LUKE Director · See Footnotes | Sold plan | $36.9k85.9k shares |
| 2026-05-19 | EVNIN LUKE Director · See Footnotes | Sold plan | $28.3k63.0k shares |
| 2026-05-18 | EVNIN LUKE Director · See Footnotes | Sold plan | $11.1k22.2k shares |
| 2026-05-13 | EVNIN LUKE Director · See Footnotes | Sold plan | $24.1k44.7k shares |
| 2026-05-12 | RA Capital Healthcare Fund LP +3 10% owner · See footnotes | Sold | $64.7k101.2k shares |
| 2026-05-12 | EVNIN LUKE Director · See Footnotes | Sold plan | $43.4k67.9k shares |
| 2026-05-11 | RA Capital Healthcare Fund LP +3 10% owner · See footnotes | Sold | $58.6k87.5k shares |
The latest 30 of 42 trades.
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| RA CAPITAL MANAGEMENT, L.P. 0.01% of their portfolio | 2.4m $859.3k | Reduced -4.3m |
| Balyasny Asset Management L.P. 0.00% of their portfolio | 1.8m $644.3k | New |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 1.2m $438.5k | Unchanged |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 674.6k $242.8k | Added +158.4k |
| Lynx1 Capital Management LP 0.03% of their portfolio | 657.8k $236.7k | Unchanged |
| SPHERA FUNDS MANAGEMENT LTD. 0.03% of their portfolio | 626.8k $225.6k | Unchanged |
| DC Funds, LP 16.92% of their portfolio | 589.1k $212.0k | Unchanged |
| Verdad Advisers, LP 0.12% of their portfolio | 348.7k $125.5k | Added +318.9k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 335.8k $120.9k | Reduced -53.7k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 311.5k $111.8k | Added +46.9k |
| XTX Topco Ltd 0.00% of their portfolio | 271.5k $97.7k | Added +220.5k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 251.8k $90.6k | Added +169.0k |
| UBS Group AG 0.00% of their portfolio | 215.8k $77.7k | Added +149.0k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 157.7k $56.8k | Unchanged |
| STATE STREET CORP 0.00% of their portfolio | 119.2k $42.9k | Unchanged |
| Squarepoint Ops LLC 0.00% of their portfolio | 103.2k $37.2k | New |
| BlackRock, Inc. 0.00% of their portfolio | 101.6k $36.6k | Reduced -35 |
| Rangeley Capital, LLC 0.03% of their portfolio | 100.0k $36.0k | New |
| NORTHERN TRUST CORP 0.00% of their portfolio | 86.9k $31.3k | Unchanged |
| Alyeska Investment Group, L.P. 0.00% of their portfolio | 86.6k $31.2k | Unchanged |
| MPM BIOIMPACT LLC 0.00% of their portfolio | 80.1k $28.9k | Reduced -1.1m |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 62.1k $22.3k | Reduced -70.0k |
| Virtu Financial LLC 0.00% of their portfolio | 45.5k $16.0k | New |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 27.3k $9.8k | New |
| GSA CAPITAL PARTNERS LLP 0.00% of their portfolio | 27.1k $10.0k | New |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 20.0k $7.2k | Reduced -18.2k |
| StoneX Group Inc. 0.00% of their portfolio | 20.0k $9.0k | New |
| MORGAN STANLEY 0.00% of their portfolio | 19.1k $6.9k | Reduced -14.7k |
| CERTUITY, LLC 0.00% of their portfolio | 15.0k $5.4k | Unchanged |
| BARCLAYS PLC 0.00% of their portfolio | 13.2k $4.8k | Unchanged |
| HBK Sorce Advisory LLC 0.00% of their portfolio | 13.2k $5.3k | Unchanged |
| Larson Financial Group LLC 0.00% of their portfolio | 13.1k $4.7k | Unchanged |
| LPL Financial LLC 0.00% of their portfolio | 11.8k $4.2k | Added +1.8k |
| Ranch Capital Advisors Inc. 0.00% of their portfolio | 11.0k $4.0k | Reduced -1.0k |
| Marest Capital, LLC 0.00% of their portfolio | 10.9k $3.9k | New |
| Cetera Investment Advisers 0.00% of their portfolio | 10.2k $3.7k | Unchanged |
| Tower Research Capital LLC (TRC) 0.00% of their portfolio | 9.9k $3.6k | New |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 8.6k $3.1k | Unchanged |
| Financial Perspectives, Inc 0.00% of their portfolio | 6.8k $2.4k | Unchanged |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 2.1k $650 | Added +12 |
| GROUP ONE TRADING LLC 0.00% of their portfolio | 1.9k $673 | Unchanged |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 790 $284 | Unchanged |
| SIMPLEX TRADING, LLC 0.00% of their portfolio | 255 $91 | Reduced -32.3k |
| SBI Securities Co., Ltd. 0.00% of their portfolio | 100 $36 | Added +20 |
| Optiver Holding B.V. 0.00% of their portfolio | 22 $8 | Unchanged |