Mplx Insider Ownership

NYSE MPLX

$58.04 -0.14 (-0.24%)

As of: Oct 20, 2026 · 2:09 PM EDT

Insider Holdings by Owner

1.42Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026

Insider Ownership

0.170%

▲+0.0010% pp QoQ

Shares Held by Insiders

1.73Mn

filed for Sep 2026

▲+0.56% QoQ

Shares Outstanding

1.02Bn

1,015,000,000 shares

Direct Holdings

1.17Mn

Indirect: 561.79K

Net Shares Traded (QoQ)

+9.70K

net buying in Sep 2026

Insiders Holding Shares

with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold

Latest quarter —

Net over range —

Buying quarters —

Insider Ownership Summary

Updated Oct 11, 2026

Over the trailing 12 months, MPLX insiders made no open-market trades in the stock.

In transactions other than open-market trades, MPLX insiders received 112.23K shares in stock awards and gave up 25.84K shares to cover taxes or exercise prices over the past 12 months.
Business Quant data shows MPLX insiders holding 1.73Mn shares in total in their latest Form 4 filings, up 0.56% from 1.72Mn shares at the end of Q2 2026 and up 2.38% from 1.69Mn shares at the end of Q3 2025.
Of the 1.73Mn shares held by MPLX insiders, 1.17Mn shares (67.52%) are held directly and 561.79K shares (32.48%) indirectly, through trusts, partnerships, family members and other entities.
MPLX's insider total is spread across 15 insiders who have filed a Form 4 in the past two years.
MPLX's three largest insider shareholders, based on their latest Form 4 filings, are Frank M. Semple (Director, 556.77K shares), Michael J. Hennigan (Executive Chairman, 359.14K shares) and Maryann T. Mannen (Chairman, President & CEO, 165.46K shares).
The largest insider, Frank M. Semple, holds 32.19% of MPLX's insider total.
Institutions accounted for 18.79% of MPLX's outstanding shares in Q2 2026, insiders about 0.17% per their latest Form 4 filings, and other investors, including the public, about 81.04%.
In the last 12 months, 45 Form 4 filings with transactions in MPLX stock came from 14 insiders.
The insider holdings and trades above for MPLX reflect Form 4 filings through August 18, 2026.

Form 4 Holdings

Insiders Holding MPLX

Insiders 19

Shares held 1.42Mn

Of outstanding 0.139%

#	Insider	Position	Direct	Total	Share of Insiders	Last Filed
1	Michael J Hennigan	Executive Chairman	359,137	359,137	25.4%	16 Dec, 2025
2	Maryann T. Mannen	Chairman, President Ceo	165,459	165,459	11.7%	03 Mar, 2026
3	Dan D Sandman	Director	127,542	127,542	9.0%	05 Apr, 2023
4	John P Surma	Director	95,448	95,448	6.7%	18 Aug, 2026
5	Gregory Scott Floerke	Exec. Vp And Coo	95,337	95,337	6.7%	03 Mar, 2026
6	Christopher A Helms	Director	86,208	86,208	6.1%	18 Aug, 2026
7	Garry L. Peiffer	President	69,313	69,313	4.9%	18 Aug, 2026
8	Suzanne Gagle	General Counsel	67,205	67,205	4.7%	05 Dec, 2023
9	Frank M Semple	Vice Chairman	63,476	63,476	4.5%	18 Aug, 2026
10	J Michael Stice	Director	58,413	58,413	4.1%	18 Aug, 2026
11	John J Quaid	Exec Vp And Cfo	52,393	52,393	3.7%	04 Mar, 2025
12	Molly R Benson	Chief Legal Ofc Corp Sec	46,114	46,114	3.3%	03 Mar, 2026
13	Timothy J Aydt	Exec. Vp And Chief Comm Ofc.	34,371	34,371	2.4%	03 Mar, 2022
14	Shawn M Lyon	Senior Vp, Log. Storage	28,289	28,289	2.0%	03 Mar, 2026
15	Carl Kristopher Hagedorn	Exec Vp Chief Fin Ofc	20,409	20,409	1.4%	03 Mar, 2026
16	Thomas Kaczynski	Senior Vp, Finance Treasurer	18,091	18,091	1.3%	06 Dec, 2022
17	Christine S Breves	Director	15,038	15,038	1.1%	18 Aug, 2026
18	Maria A Khoury	Director	8,451	8,451	0.6%	03 Mar, 2026
19	Ray N Jr Walker	Director	4,609	4,609	0.3%	18 Aug, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

1,269 Insider Transactions

Source SEC Form 4

Latest quarter Sep 2026

Date	Insider	Position	Transaction	Shares	Price	Value	Shares Held After	Ownership
14 Aug, 2026	Christine S Breves	Director	Acquired A	219	$0.00	$0	15,038	Direct
14 Aug, 2026	Frank M Semple	Director	Acquired A	1,073	$0.00	$0	63,476	Direct
14 Aug, 2026	J Michael Stice	Director	Acquired A	983	$0.00	$0	58,413	Direct
14 Aug, 2026	Ray N Jr Walker	Director	Acquired A	82	$0.00	$0	4,609	Direct
14 Aug, 2026	Garry L. Peiffer	Director	Acquired A	1,232	$0.00	$0	69,313	Direct
14 Aug, 2026	Christopher A Helms	Director	Acquired A	1,337	$0.00	$0	86,208	Direct
14 Aug, 2026	John P Surma	Director	Acquired A	1,563	$0.00	$0	95,448	Direct
15 May, 2026	John P Surma	Director	Acquired A	1,656	$0.00	$0	93,426	Direct
15 May, 2026	Ray N Jr Walker	Director	Acquired A	78	$0.00	$0	4,069	Direct
15 May, 2026	Christopher A Helms	Director	Acquired A	1,415	$0.00	$0	84,413	Direct
15 May, 2026	Garry L. Peiffer	Director	Acquired A	1,304	$0.00	$0	67,623	Direct
15 May, 2026	J Michael Stice	Director	Acquired A	1,098	$0.00	$0	56,973	Direct
15 May, 2026	Frank M Semple	Director	Acquired A	1,194	$0.00	$0	61,946	Direct
15 May, 2026	Christine S Breves	Director	Acquired A	277	$0.00	$0	14,361	Direct
30 Apr, 2026	Christine S Breves	Director	Acquired A	2,247	$0.00	$0	14,084	Direct
30 Apr, 2026	Ray N Jr Walker	Director	Acquired A	2,247	$0.00	$0	3,991	Direct
30 Apr, 2026	Garry L. Peiffer	Director	Acquired A	2,247	$0.00	$0	66,319	Direct
30 Apr, 2026	J Michael Stice	Director	Acquired A	2,580	$0.00	$0	55,875	Direct
30 Apr, 2026	Frank M Semple	Director	Acquired A	2,580	$0.00	$0	60,752	Direct
30 Apr, 2026	Christopher A Helms	Director	Acquired A	2,247	$0.00	$0	82,998	Direct

Showing 1 to 20 of 1,269 transactions