MPM BioVentures 2014 (B), L.P.

CIK 1609493 · last filed 2025-11-12

MPM BioVentures 2014 (B), L.P. is a corporate insider who has filed 24 SEC Form 4 insider transactions across 3 companies since 2021. The most recent filing, for HOWL, was dated Jul 6, 2026. Across all open-market trades the lifetime net is −$43.6M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $32.9M across reported positions.

"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

$32.95M

Companies

3

Total Filings

24

Lifetime Open-Market Net

-$43.64M

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 10%+ Owner 5,731,860 $0.38 $2.19M -$1.21M 1 2025-11-12
iTeos Therapeutics, Inc. (ITOS) Delisted 10%+ Owner 2,771,359 $10.15 $28.13M -$60.44M 2 2022-01-06
TRDA 10%+ Owner 4,425,784 $6.95 $30.76M $18.00M 1 2021-11-04

Recent Filings

24 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) −6,459 -$2.2K EDGAR
2026-06-29 HOWL Notice (144) −7,087 -$2.3K EDGAR
2026-05-28 HOWL Notice (144) −16,287 -$8.0K EDGAR
2026-05-18 HOWL Notice (144) −19,370 -$10.0K EDGAR
2026-05-11 HOWL Notice (144) −5,635 -$3.8K EDGAR
2026-05-01 HOWL Notice (144) −24,251 -$17.5K EDGAR
2026-04-29 HOWL Notice (144) −8,678 -$6.4K EDGAR
2026-04-27 HOWL Notice (144) −8,678 -$7.1K EDGAR
2026-01-06 HOWL Notice (144) −13,256 -$8.5K EDGAR
2025-12-29 HOWL Notice (144) −8,679 -$5.7K EDGAR
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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.