MPM BioImpact LLC insider trades: Werewolf Therapeutics (HOWL) stock buys and sales
Trades on the price chart
Daily close, with an arrow on each day they bought or sold
Companies
Where MPM BioImpact LLC reports to the SEC
and 1 more company
Open-market buys and sales
58 trades reported on SEC Form 4, newest first
| Date | Stock | Type | Shares | Price | Value | Holding | Reported |
|---|---|---|---|---|---|---|---|
| Dec 4, 2025 | HOWL | ↓ Sell | 199,732 | $0.92 | $183K | Indirect | Dec 4, 2025 (0d) |
| Dec 1, 2025 | HOWL | ↓ Sell | 141,927 | $0.96 | $137K | Indirect | Dec 1, 2025 (0d) |
| Nov 25, 2025 | HOWL | ↓ Sell | 195,666 | $0.92 | $180K | Indirect | Nov 25, 2025 (0d) |
| Nov 20, 2025 | HOWL | ↓ Sell | 160,103 | $0.92 | $148K | Indirect | Nov 20, 2025 (0d) |
| Nov 17, 2025 | HOWL | ↓ Sell | 209,652 | $0.96 | $201K | Indirect | Nov 17, 2025 (0d) |
| Nov 12, 2025 | HOWL | ↓ Sell | 213,529 | $1.13 | $241K | Indirect | Nov 12, 2025 (0d) |
| Nov 6, 2025 | HOWL | ↓ Sell | 242,890 | $1.22 | $296K | Indirect | Nov 6, 2025 (0d) |
| Nov 3, 2025 | HOWL | ↓ Sell | 295,043 | $1.33 | $392K | Indirect | Nov 3, 2025 (0d) |
| Oct 29, 2025 | HOWL | ↓ Sell | 276,017 | $1.62 | $446K | Indirect | Oct 29, 2025 (0d) |
| May 13, 2025 | ITOS | ↓ Sell | 1,031,931 | $8.06 | $8.3M | Indirect | May 15, 2025 (2d) |
| Mar 27, 2025 | HOWL | ↓ Sell | 4,386 | $1.05 | $5K | Indirect | Apr 30, 2025 (34d) |
| Jan 5, 2022 | ITOS | ↓ Sell | 245,469 | $42.58 | $10.5M | Indirect | Jan 6, 2022 (1d) |
| Dec 7, 2021 | ITOS | ↓ Sell | 83,390 | $33.73 | $2.8M | Indirect | Dec 7, 2021 (0d) |
| Dec 2, 2021 | ITOS | ↓ Sell | 139,773 | $34.47 | $4.8M | Indirect | Dec 2, 2021 (0d) |
| Nov 29, 2021 | ITOS | ↓ Sell | 38,566 | $35.18 | $1.4M | Indirect | Nov 30, 2021 (1d) |
| Nov 24, 2021 | ITOS | ↓ Sell | 129,617 | $36.61 | $4.7M | Indirect | Nov 24, 2021 (0d) |
| Oct 18, 2021 | ITOS | ↓ Sell | 28,615 | $27.45 | $785K | Indirect | Oct 18, 2021 (0d) |
| Oct 14, 2021 | ITOS | ↓ Sell | 95,002 | $27.21 | $2.6M | Indirect | Oct 14, 2021 (0d) |
| Oct 11, 2021 | ITOS | ↓ Sell | 87,006 | $27.23 | $2.4M | Indirect | Oct 12, 2021 (1d) |
| Oct 4, 2021 | ITOS | ↓ Sell | 46,130 | $27.05 | $1.2M | Indirect | Oct 5, 2021 (1d) |
| Sep 30, 2021 | ITOS | ↓ Sell | 35,990 | $27.00 | $972K | Indirect | Sep 30, 2021 (0d) |
| Sep 27, 2021 | ITOS | ↓ Sell | 89,476 | $27.76 | $2.5M | Indirect | Sep 27, 2021 (0d) |
| Sep 22, 2021 | ITOS | ↓ Sell | 56,779 | $27.50 | $1.6M | Indirect | Sep 23, 2021 (1d) |
| Sep 20, 2021 | ITOS | ↓ Sell | 152,711 | $28.38 | $4.3M | Indirect | Sep 20, 2021 (0d) |
| Sep 16, 2021 | CGEM | ↓ Sell | 3,124 | $29.06 | $91K | Direct | Sep 20, 2021 (4d) |
| Sep 15, 2021 | ITOS | ↓ Sell | 76,417 | $27.70 | $2.1M | Indirect | Sep 16, 2021 (1d) |
| Sep 15, 2021 | CGEM | ↓ Sell | 13,531 | $29.17 | $395K | Direct | Sep 16, 2021 (1d) |
| Sep 13, 2021 | ITOS | ↓ Sell | 96,456 | $28.32 | $2.7M | Indirect | Sep 13, 2021 (0d) |
| Sep 13, 2021 | CGEM | ↓ Sell | 23,253 | $29.23 | $680K | Direct | Sep 13, 2021 (0d) |
| Sep 8, 2021 | ITOS | ↓ Sell | 71,232 | $29.03 | $2.1M | Indirect | Sep 8, 2021 (0d) |
| Sep 8, 2021 | CGEM | ↓ Sell | 48,640 | $29.20 | $1.4M | Direct | Sep 8, 2021 (0d) |
| Sep 2, 2021 | CGEM | ↓ Sell | 24,309 | $29.50 | $717K | Direct | Sep 2, 2021 (0d) |
| Aug 30, 2021 | CGEM | ↓ Sell | 44,358 | $29.24 | $1.3M | Direct | Aug 31, 2021 (1d) |
| Aug 25, 2021 | CGEM | ↓ Sell | 105,894 | $29.29 | $3.1M | Direct | Aug 25, 2021 (0d) |
| Aug 11, 2021 | CGEM | ↓ Sell | 2,510 | $29.05 | $73K | Direct | Aug 12, 2021 (1d) |
| Jun 2, 2021 | HARP | ↓ Sell | 57,494 | $20.63 | $1.2M | Indirect | Jun 2, 2021 (0d) |
| May 27, 2021 | HARP | ↓ Sell | 17,159 | $20.22 | $347K | Indirect | May 27, 2021 (0d) |
| May 24, 2021 | HARP | ↓ Sell | 15,907 | $20.18 | $321K | Indirect | May 24, 2021 (0d) |
| May 20, 2021 | HARP | ↓ Sell | 47,948 | $20.49 | $982K | Indirect | May 20, 2021 (0d) |
| May 17, 2021 | HARP | ↓ Sell | 16,421 | $20.05 | $329K | Indirect | May 17, 2021 (0d) |
| May 12, 2021 | HARP | ↓ Sell | 68,262 | $21.04 | $1.4M | Indirect | May 12, 2021 (0d) |
| May 5, 2021 | HARP | ↓ Sell | 10,172 | $22.52 | $229K | Indirect | May 6, 2021 (1d) |
| May 4, 2021 | HOWL | ↑ Buy | 245,000 | $16.00 | $3.9M | Indirect | May 6, 2021 (2d) |
| May 4, 2021 | HARP | ↓ Sell | 328,519 | $22.48 | $7.4M | Indirect | May 4, 2021 (0d) |
| Apr 29, 2021 | HARP | ↓ Sell | 130,143 | $21.99 | $2.9M | Indirect | Apr 29, 2021 (0d) |
| Apr 21, 2021 | HARP | ↓ Sell | 8,972 | $18.97 | $170K | Indirect | Apr 22, 2021 (1d) |
| Apr 20, 2021 | HARP | ↓ Sell | 38,152 | $19.04 | $727K | Indirect | Apr 20, 2021 (0d) |
| Apr 15, 2021 | HARP | ↓ Sell | 38,556 | $20.16 | $777K | Indirect | Apr 15, 2021 (0d) |
| Apr 12, 2021 | HARP | ↓ Sell | 30,928 | $21.90 | $677K | Indirect | Apr 13, 2021 (1d) |
| Apr 9, 2021 | ITOS | ↓ Sell | 200 | $29.99 | $6K | Indirect | Apr 13, 2021 (4d) |
Each row is one filing's trades in one stock, summed. Shares and prices are as filed, before any later stock split.
Other HOWL insiders
Open-market trades in the last 12 months
About MPM BioImpact LLC's insider trades
MPM BioImpact LLC is an insider at Werewolf Therapeutics (HOWL). Since Nov 6, 2017, it has reported 7 open-market purchases worth $32.3M and 51 sales worth $84.5M on SEC Form 4. In the last 12 months: 7 sales ($1.4M).
Its filings also include conversions (6 filings), other transactions (4 filings), option exercises (2 filings). These aren't open-market trades and aren't counted above.
How to read insider trades
Officers, directors and owners of more than 10% of a company must report trades in its stock on SEC Form 4, usually within two business days. Purchases with their own money are the stronger signal: insiders sell for many reasons (taxes, diversification, a house), but buy for one. See every HOWL insider trade, the latest insider trades across the market, or cluster buys, when several insiders buy the same stock within days.