MPC

Marathon Petroleum Corp

NYSEIndustrialsPetroleum Refining

Insider activity for last month from 08/03 to 09/03. Counts use processed Form 4 rows. Purchase and sale metrics use codes P and S; totals remain unknown when any matching value is missing. Rows without a usable transaction date cannot be assigned to a rolling period and are excluded.

Latest filingSep 01, 2026Most recent Form 4
Total buying$00 buys
Total selling$598M6 sells
Net open-market-$598M3 insiders
Open-market mix
Buy vs sell distribution by transaction count
6 transactions
0 buys0%·100%6 sells

Insider activity report

Monthly open-market purchase and sale counts
Buys Sells
1050-5-10transactionsAug 2026 sells: 6 transactions · $598M6AugSep

Transaction codes

By Form 4 transaction code in selected period
11transactions
  • S · Open-market sells · dominant6 · 55%
  • M · Option exercise5 · 45%

Activity by reported role

A joint filing can contribute to multiple roles
22transactions
  • CLO · dominant7 · 32%
  • CS7 · 32%
  • MGL3 · 14%
  • SL3 · 14%
  • CTRL1 · 5%
  • VP1 · 5%

Distinct insiders active

Reporting-owner CIKs by month · peak Aug 2026 (3)
Aug 2026Sep 2026
3distinct insiders in 2 months

Reported Holdings After

Separated by insider, security, and ownership type
Benson Molly RCommon Stock · Direct
37.5k30.3kAug 17, 2026 · 35,334.3328 shares owned afterAug 17, 2026 · 37,530.3328 shares owned afterAug 17, 2026 · 30,334.3328 shares owned afterAug 17, 2026 · 30,334.3328 shares owned afterAug 17, 2026Aug 17, 2026
30,334.3328Aug 17, 2026
Lyon Shawn MCommon Stock · Direct
12.6k11.2kAug 13, 2026 · 12,619 shares owned afterAug 28, 2026 · 12,194 shares owned afterAug 31, 2026 · 11,194 shares owned afterAug 13, 2026Aug 31, 2026
11,194Aug 31, 2026
Benson Molly REmployee Stock Option (right to buy) · Direct
10.0k0Aug 17, 2026 · 10,000 shares owned afterAug 17, 2026 · 5,000 shares owned afterAug 17, 2026 · 0 shares owned afterAug 17, 2026Aug 17, 2026
0Aug 17, 2026
Brzezinski Erin MCommon Stock · Direct
1.6k1.6kAug 27, 2026 · 1,576 shares owned afterAug 27, 2026Aug 27, 2026
1,576Aug 27, 2026

These are reported post-transaction holdings, not company-wide ownership percentages. Securities, indirect vehicles, and amendments are kept separate.

Filing activity heatmap
Each cell is one day · intensity = transactions · buys green, sells red
4 active days
Aug 03Sep 03
LessMore
Top insiders
By absolute net value across the selected period
3 insiders
  • BR
    Benson Molly RCLO, CS · rank 1 · 0 buys · 2 sells
    -$3.8Mlast 08/19/undefined
  • LM
    Lyon Shawn MSL, MGL · rank 2 · 0 buys · 3 sells
    -$1.4Mlast 09/01/undefined
  • BM
    Brzezinski Erin MVP, CTRL · rank 3 · 0 buys · 1 sells
    -$206.8klast 08/31/undefined
Recent filing activity
Most recent 11 transactions · color = transaction code

Filing detail checks

Secondary metrics for the selected period
Largest buy-
Largest sale$258M
10b5-1 detected7
Amended rows0

MPC transaction history

Filters apply within this company and selected period by default
Reset
TickerInsiderRoleTypeSharesValueCodeSignals90d returnFiledTrans date
MPCLyon Shawn M
SLMGL
sale1.00k-$37.5MS0.0%09/0108/31
MPCLyon Shawn M
SLMGL
sale425-$15.6MS0.0%09/0108/28
MPCBrzezinski Erin M
VPCTRL
sale570-$20.6MS0.0%08/3108/27
MPCBenson Molly R
CLOCS
exercise10b5-15.00k$0M+6.2%08/1908/17
MPCBenson Molly R
CLOCS
exercise10b5-15.00k$0M+6.2%08/1908/17
MPCBenson Molly R
CLOCS
exercise10b5-17.19k$0M+6.2%08/1908/17
MPCBenson Molly R
CLOCS
sale10b5-15.00k-$179MS+6.2%08/1908/17
MPCBenson Molly R
CLOCS
exercise10b5-15.00k$23.8MM+6.2%08/1908/17
MPCBenson Molly R
CLOCS
sale10b5-17.19k-$258MS+6.2%08/1908/17
MPCBenson Molly R
CLOCS
exercise10b5-17.19k$34.3MM+6.2%08/1908/17
MPCLyon Shawn M
SLMGL
sale2.50k-$87.5MS+6.9%08/1708/13

Marathon Petroleum Corp Insider Activity FAQ

SEC Form 4 context

Who recently reported transactions at Marathon Petroleum Corp?

Lyon Shawn M, Brzezinski Erin M, Benson Molly R.

When was the latest reported open-market purchase?

No code-P purchase is available for this period.

When was the latest reported open-market sale?

Lyon Shawn M reported a sale on Aug 31, 2026 valued at $37.5M. Read the SEC filing.

What is the recent purchase and sale balance?

Net open-market selling in the selected period was $5,987,276.77. Sales can occur for many non-investment reasons.

Where can I see the original SEC filing?

Every transaction row and latest-activity fact links to its original SEC filing.

What do these Form 4 transaction codes mean?

P and S generally describe open-market or private purchases and sales. A, D, F, M, X, G, J, and V describe awards, issuer dispositions, tax withholding, exercises, gifts, other transactions, and voluntary early reports; review each filing and its footnotes for context.