MPM BioImpact LLC HOWL — Werewolf Therapeutics, Inc.

Ownership history in MPM BioImpact LLC  ·  20 quarters on record

AI Ownership Summary

MPM BioImpact LLC reported Werewolf Therapeutics, Inc. (HOWL) in 20 quarterly 13F filings from 2023 Q4 through 2026 Q1. Peak portfolio weight reached 2.49% in 2024 Q1. The latest visible filing shows HOWL at 0.08% of the fund.

This page tracks quarterly shares, estimated market value, portfolio weight, filing dates, and disclosure-aligned stock prices directly from SEC EDGAR 13F filings. Older history is available after unlock; the visible window still shows the most recent pattern.

What this HOWL ownership page tells you

This page is designed to answer the real investor question behind a 13F filing: how meaningful was MPM BioImpact LLC's position in Werewolf Therapeutics, Inc., and how did that conviction change over time? You can read the holding window, peak weight, latest reported size, disclosure timing, and quarter-by-quarter changes without piecing the story together from raw SEC rows.

Freshest filing
Latest Reported Filing
2026 Q1

HOWL was reported at 0.08% of portfolio in the most recent visible filing.

High-water mark
Peak Conviction
2.49% in 2024 Q1

Peak weight helps separate a token disclosure from a real conviction holding the fund genuinely cared about.

Time in book
Holding Window
2023 Q4 to 2026 Q1

Longer holding windows often tell a very different story from short-lived tactical trades or one-quarter experiments.

Decision context
Why It Matters
Position size beats headlines

Knowing that a fund owned a stock is useful. Knowing whether it was a 0.20% placeholder or a true high-conviction position is where the signal actually starts.

HOWL stock page MPM BioImpact LLC fund profile MPM BioImpact LLC full holdings
How MPM BioImpact LLC held HOWL — position size vs. price
% of Fund (quarterly)    HOWL price (quarter-end, indexed to 100)    SPY (indexed to 100)    QQQ (indexed to 100)
📋 Quarterly Holdings History 10 quarters  ▾
Quarter Action Sold % After 3M Timing Shares Change Chg % % of Fund Mkt Value Filed Price (Filed)
2026 Q1 REDUCED — — — 1,208,810 -184,747 -13.3% 0.08% $1.0M 2026-05-15 $0.51
2025 Q4 REDUCED 42.1% +31.8% ❌ 1,393,557 -1,015,253 -42.1% 0.10% $884K 2026-02-17 $0.66
2025 Q3 UNCHANGED — — — 2,408,810 — 0% 0.78% $4.7M 2025-11-14 $0.92
2025 Q2 UNCHANGED — — — 2,408,810 — 0% 0.45% $2.6M 2025-08-14 $1.32
2025 Q1 ADDED — — — 2,408,810 +20,799 +0.9% 0.40% $2.3M 2025-05-15 $1.11
2024 Q4 UNCHANGED — — — 2,388,011 — 0% 0.50% $3.5M 2025-02-14 $1.49
2024 Q3 UNCHANGED — — — 2,388,011 — 0% 0.76% $5.1M 2024-11-13 $2.05
2024 Q2 UNCHANGED — — — 2,388,011 — 0% 0.91% $5.8M 2024-08-14 $1.99
2024 Q1 UNCHANGED — — — 2,388,011 — 0% 2.49% $15.5M 2024-05-15 $4.85
2023 Q4 UNCHANGED — — — 2,388,011 — 0% 2.16% $9.2M 2024-02-13 $5.87
10 older quarters hidden  —  Sign in free or upgrade to Premium to see full history

🏢 Other funds also holding HOWL

As of 2026 Q1 — sorted by position size

DC Funds, LP 3Y 33.01% Squadron Capital Management LLC 0.17% Lynx1 Capital Management LP 3Y 0.09% SPHERA FUNDS MANAGEMENT LTD. 3Y 7Y 0.08% RA CAPITAL MANAGEMENT, L.P. 3Y 7Y 0.06% Verdad Advisers, LP 3Y 0.03% Ranch Capital Advisors Inc. 3Y 0.0% Delta Investment Management, LLC 3Y 7Y 0.0% Financial Perspectives, Inc 0.0% BRIDGEWAY CAPITAL MANAGEMENT, LLC 3Y 7Y 0.0%

FAQ About MPM BioImpact LLC and HOWL

These are the practical questions this page is built to answer before you even open the full history table.

How long has MPM BioImpact LLC reported owning HOWL?

MPM BioImpact LLC reported HOWL across 10 quarterly 13F filings, from 2023 Q4 through 2026 Q1.

What was the largest reported HOWL position in MPM BioImpact LLC's portfolio?

The largest reported portfolio weight for HOWL was 2.49% in 2024 Q1.

What is the latest reported HOWL position on this page?

The most recent filing on this page is 2026 Q1, when MPM BioImpact LLC reported 1,208,810 shares, equal to 0.08% of portfolio, with an estimated market value of $1.0M.

What does the chart on this HOWL ownership page compare?

The chart compares MPM BioImpact LLC's quarterly HOWL portfolio weight with the stock's indexed share price, so you can see whether the fund was building, trimming, or holding the position as price moved.

How well did MPM BioImpact LLC time their HOWL position?

Based on 13F filing dates vs. subsequent HOWL price moves, MPM BioImpact LLC correctly timed 3 out of 3 reported position changes (100%). The annualised alpha on HOWL relative to SPY over the holding period was -55.0%.

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