MPM ASSET MANAGEMENT LLC

CIK 1263048 · last filed 2026-01-14

MPM ASSET MANAGEMENT LLC is a corporate insider who has filed 7 SEC Form 4 insider transactions across 3 companies since 2010. The most recent filing, for AKTS, was dated Jan 14, 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 $161.6M 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

$161.62M

Companies

3

Total Filings

7

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 $21.10 $159.73M $60.09M 1 2026-01-14
HOWL 10%+ Owner 4,784,111 $0.39 $1.89M -$3.93M 3 2025-12-04
EPIRUS Biopharmaceuticals, Inc. (CRXX) Delisted 10%+ Owner 14,633,961 $0 1 2010-01-04

Recent Filings

7 filings
Form 4 transactions across all companies, newest first.
Filed Symbol Action Net Shares Net $ Link
2026-01-14 AKTS Mixed +29,755,065 $60.09M EDGAR
2025-12-04 HOWL Sell (S) −1,398,124 -$1.28M EDGAR
2025-12-01 HOWL Sell (S) −993,489 -$958.0K EDGAR
2025-11-12 HOWL Sell (S) −1,494,703 -$1.69M EDGAR
2011-10-21 Sell (S) −3,678,536 -$3.79M
2011-10-06 Sell (S) −3,041,856 -$3.10M
2010-01-04 EPIRUS Biopharmaceuticals, Inc. (CRXX) Delisted Other (J) −63,309,224 $0 EDGAR
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.