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MICHAEL E PORTER

CIK 1108494 · last filed 2017-09-15

MICHAEL E PORTER is a corporate insider who has filed 83 SEC Form 4 insider transactions across 5 companies since 2007. The most recent filing, for MACK, was dated Sep 15, 2017. Across all open-market trades the lifetime net is −$1.8M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $37.8M 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

$37.79M

Companies

5

Total Filings

83

Lifetime Open-Market Net

-$1.81M

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
MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Director 839,448 $15.13 $12.70M $2.57M 31 2017-09-15
PTC Director 231,599 $115.72 $26.80M -$371.8K 4 2015-03-05
SMG Director 22,204 $69.91 $1.55M $118.1K 15 2015-02-02
PTC INC. (PMTC) Delisted Director 220,579 — — -$1.51M 16 2013-12-02
TMO Director 18,390 $513.03 $9.43M -$2.62M 17 2012-03-12

Recent Filings

83 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
2017-09-15 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Grant (A) — $0 EDGAR
2017-03-13 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Exer (M) +85,000 $228.7K EDGAR
2016-06-16 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Grant (A) — $0 EDGAR
2016-03-21 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Buy (P) +5,000 $36.0K EDGAR
2016-03-17 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Buy (P) +5,000 $38.2K EDGAR
2016-03-10 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Buy (P) +10,000 $70.9K EDGAR
2016-03-04 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Buy (P) +15,000 $95.8K EDGAR
2016-03-02 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Buy (P) +20,000 $122.1K EDGAR
2015-08-25 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Buy (P) +5,000 $48.8K EDGAR
2015-08-17 MERRIMACK PHARMACEUTICALS INC (MACK) Delisted Buy (P) +13,000 $137.0K EDGAR
Showing 1–10 of 83
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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.