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MPM BioVentures 2014, L.P.

CIK 1609492 · last filed 2025-12-04

MPM BioVentures 2014, L.P. is a corporate insider who has filed 22 SEC Form 4 insider transactions across 3 companies since 2019. The most recent filing, for HOWL, was dated Jul 6, 2026. Across all open-market trades the lifetime net is +$114.3M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $4.7M across reported positions. The firm reports its address in Boston, MA. 57 SEC filings were submitted jointly with MPM Asset Management Investors BV2014 LLC.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

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Disclosed Exposure

$4.70M

Companies

3

Total Filings

22

Lifetime Open-Market Net

$114.28M

Filer Profile

Reported Address
C/O MPM BIOIMPACT
399 BOYLSTON STREET, SUITE 1100
BOSTON, MA 02116
Phone
(617) 425-9200
State of Incorporation
DE
Related Filers
MPM Asset Management Investors BV2014 LLC — 57 joint filings, latest 2026-08-31
MPM BioVentures 2014 (B), L.P. — 57 joint filings, latest 2026-08-31
MPM BioVentures 2014 GP LLC — 54 joint filings, latest 2026-08-31
MPM BioVentures 2014 LLC — 54 joint filings, latest 2026-08-31
Todd Foley — 41 joint filings, latest 2026-08-31
LUKE EVNIN — 38 joint filings, latest 2026-08-31
MPM ASSET MANAGEMENT INVESTORS BV2018 LLC — 26 joint filings, latest 2026-08-31
MPM BIOVENTURES 2018 (B), L.P. — 26 joint filings, latest 2026-08-31
Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
HOWL 4,867,341 $0.96 $4.70M -$916.4K 1 2025-12-04
iTeos Therapeutics, Inc. (ITOS) Delisted 10%+ Owner 69,951 $10.15 $710.0K $30.40M 1 2020-07-29
TCR2 THERAPEUTICS INC. (TCRR) Delisted 10%+ Owner 3,021,298 $1.48 $4.47M $84.80M 1 2019-02-21

Recent Filings

22 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2026-07-06 HOWL Notice (144) −96,873 -$33.0K EDGAR
2026-06-29 HOWL Notice (144) −106,262 -$34.3K EDGAR
2026-05-28 HOWL Notice (144) −244,185 -$119.7K EDGAR
2026-05-18 HOWL Notice (144) −290,419 -$149.6K EDGAR
2026-05-11 HOWL Notice (144) −84,491 -$57.5K EDGAR
2026-05-01 HOWL Notice (144) −363,593 -$261.6K EDGAR
2026-04-29 HOWL Notice (144) −130,115 -$96.3K EDGAR
2026-04-27 HOWL Notice (144) −130,115 -$105.8K EDGAR
2026-01-06 HOWL Notice (144) −198,739 -$128.1K EDGAR
2025-12-29 HOWL Notice (144) −130,125 -$85.1K EDGAR
Showing 1–10 of 22
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Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.