Home

MPM ASSET MANAGEMENT LLC

CIK 1263048 · last filed 2026-01-14

MPM ASSET MANAGEMENT LLC is a corporate insider who has filed 26 SEC Form 4 insider transactions across 3 companies since 2010. The most recent filing, for HOWL, was dated Jul 6, 2026. Across all open-market trades the lifetime net is +$56.2M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $185.4M 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.

Loading insider history…
Disclosed Exposure

$185.44M

Companies

3

Total Filings

26

Lifetime Open-Market Net

$56.16M

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
AKTS 10%+ Owner 7,570,168 $24.21 $183.27M $60.09M 1 2026-01-14
HOWL 10%+ Owner 4,784,111 $0.45 $2.17M -$3.93M 3 2025-12-04
EPIRUS Biopharmaceuticals, Inc. (CRXX) Delisted 10%+ Owner 14,633,961 — — $0 1 2010-01-04

Recent Filings

26 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) −15,341 -$5.2K EDGAR
2026-06-29 HOWL Notice (144) −16,830 -$5.4K EDGAR
2026-05-28 HOWL Notice (144) −38,675 -$19.0K EDGAR
2026-05-18 HOWL Notice (144) −45,998 -$23.7K EDGAR
2026-05-11 HOWL Notice (144) −13,382 -$9.1K EDGAR
2026-05-01 HOWL Notice (144) −57,588 -$41.4K EDGAR
2026-04-29 HOWL Notice (144) −20,608 -$15.2K EDGAR
2026-04-27 HOWL Notice (144) −20,608 -$16.8K EDGAR
2026-01-14 AKTS Mixed +29,755,065 $60.09M EDGAR
2026-01-06 HOWL Notice (144) −31,458 -$20.3K EDGAR
Showing 1–10 of 26
Page 1 of 3
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.