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Garry L. Peiffer

CIK 1521094 · Executive VP (See Remarks) · last filed 2026-08-18

Garry L. Peiffer is an Executive VP (See Remarks) who has filed 115 SEC Form 4 insider transactions across 2 companies since 2011. The most recent filing, for MPLX, was dated Aug 18, 2026. Across all open-market trades the lifetime net is +$1.6M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $35.2M across reported positions. 13 SEC filings were submitted jointly with Marathon Petroleum Corp.

"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

$35.21M

Companies

2

Total Filings

115

Lifetime Open-Market Net

$1.58M

Filer Profile

Reported Address
C/O MARATHON PETROLEUM CORPORATION
539 S. MAIN STREET
FINDLAY, OH 45840
Related Filers
Marathon Petroleum Corp — 13 joint filings, latest 2014-01-06
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
MPLX Director 137,810 $59.67 $8.22M $1.58M 103 2026-08-18
MPC Executive VP (See Remarks) 69,382 $388.90 $26.98M $0 12 2014-01-06

Recent Filings

115 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
2026-08-18 MPLX Grant (A) +1,232 $0 EDGAR
2026-08-05 MPLX Grant (A) +2,696 $0 EDGAR
2026-05-19 MPLX Grant (A) +1,303 $0 EDGAR
2026-05-04 MPLX Grant (A) +2,246 $0 EDGAR
2026-02-19 MPLX Grant (A) +1,180 $0 EDGAR
2025-11-18 MPLX Grant (A) +1,247 $0 EDGAR
2025-08-19 MPLX Grant (A) +1,157 $0 EDGAR
2025-05-20 MPLX Grant (A) +1,090 $0 EDGAR
2025-05-05 MPLX Grant (A) +2,481 $0 EDGAR
2025-04-03 MPLX Grant (A) +192 $0 EDGAR
Showing 1–10 of 115
Page 1 of 12
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.