MPLX Insider Trading

MPLX Lp (MPLX) operates in the Energy sector, specifically the Oil & Gas Midstream industry, with a market capitalization near $57.75B, listed on NYSE, employing roughly 5,762 people, carrying a beta of 0.48 to the broader market. MPLX LP, incorporated in 2012 and headquartered in Findlay, Ohio, operates as a subsidiary of Marathon Petroleum Corporation, with MPLX GP LLC serving as its general partner. Led by Maryann T. Mannen, public since 2012-10-26.

In the last 12 months, MPLX Lp insiders made 0 buy transactions and 0 sale transactions.

MPLX Insider Activity by Quarter

Reported Form 4 and Form 5 lines under MPLX's own SEC company ID, by transaction date, back to Q4 2024. Purchases and sales are code P / S (open market or private) in the company's shares; other lines are purchases and sales of other securities (options, warrants, preferred), awards, exercises, tax withholding, gifts and other acquisitions and dispositions. Later filings and amendments can change the current quarter. Earlier quarters are not shown: the filings read reach back to Jan 6, 2021, and a quarter counts only when every filing for it was read.

MPLX Institutional Ownership (13F)

As of Jun 30, 2026 (Q2 2026), 638 institutions reported holding 196,336,402 MPLX shares, valued at $11.06B as reported, 19.2% of its market cap (market cap of Jun 26, 2026). That is -8 institutions from the quarter before. Among managers whose reports for both quarters are comparable, 49 opened a position, 52 closed one, 242 added and 149 trimmed.

Top Holders, Q2 2026

By Quarter

From the SEC's Form 13F data sets: investment managers with $100 million or more in Section 13(f) securities report their holdings each quarter, up to 45 days after it ends; a restated filing replaces the original, and values are as the managers reported them (a position whose price runs about 1,000 times below other managers', from a manager whose positions mostly do, is read as reported in thousands of dollars). The same shares can be reported by more than one manager, so totals can count some twice.

ETFs Holding MPLX

From each fund's latest holdings file on record that shows MPLX's listed security itself. A file counts when its line count is consistent with the fund's reported holdings count (at most twice it plus 10, or at most 1,000 lines for a reported count of exactly 10, which the data source gives many funds as a cap), read with that file or inherited from the fund's last classified file (within 20% of its line count, read within 60 days). Funds whose line for the company could not be confirmed as MPLX's listed security, or that hold it through underlying funds (look-through), are not listed. Only long positions count: a fund is left out when any of its lines for MPLX reports a negative weight, share count or value, or none of them above zero (a short position, or figures that disagree). Shares, value and weight are as reported in each fund's file, dated by the data source's last update of that file (not the date of the positions); the weight is MPLX's share of that fund.

MPLX Congress Trades

Members of Congress and their households disclosed 8 transactions in MPLX on file (4 purchases, 4 sales) by 2 members, the latest trade on Apr 15, 2020.

From the periodic transaction reports members of the Senate and the House file under the STOCK Act, within 45 days of a trade (some file later); amounts are the ranges the reports give (a few give an exact amount), and a transaction a later report lists again is counted once. On file: House reports disclosed from Apr 10, 2023 through Oct 13, 2026; Senate reports disclosed from Jan 30, 2014 through Oct 7, 2026. The party is the member's on the trade date. A trade is listed under the company that traded under its ticker on the trade date (dated from Feb 1, 2021, unless the filing describes another company of ours; before that, only when the filing's description of the security is the company's name).

How to Read MPLX Insider Activity

Net insider activity is balanced over the trailing twelve months: 0 buys against 0 sales. Balanced activity typically reflects routine compensation-related vesting and tax-driven liquidity rather than directional information signals. The transaction table above includes the filer's reporting name, transaction type, share count, per-share price, and total dollar value where computable. For options traders, insider activity is one input to event-driven sizing alongside earnings calendar, analyst-rating cluster moves, and the implied-vol surface. Form 4 filings (the dominant Section 16 reporting form) must be submitted within two business days of the transaction; clusters of buys across multiple insiders within a short window are the strongest informational pattern. SEC EDGAR carries the underlying source filings for verification and additional historical depth.

Learn how insider trading is reported and how to read the data →

Frequently asked MPLX insider trading questions

How active are MPLX insiders right now?

Over the trailing twelve months, MPLX Lp (MPLX) insiders made 0 buy transactions and 0 sale transactions. Net insider activity over the trailing twelve months is balanced (0 buys, 0 sales). The transaction list above shows the most recent filings; each entry includes the insider's name, transaction type, share count, and per-share price.

What counts as an insider transaction?

Section 16 of the Securities Exchange Act requires officers, directors, and 10% beneficial-owner shareholders to disclose changes in their holdings via Form 3 (initial statement), Form 4 (subsequent transactions, filed within two business days), and Form 5 (annual catch-up). Insider transactions cover open-market purchases and sales, exercise of stock options, gifts, and grants. The "transaction type" field on each row distinguishes these subcategories.

Are MPLX insider buys a bullish signal?

Insider purchases (Type P, made on the open market or privately; the code covers both) carry more informational weight than insider sales: an insider must commit personal capital, and the SEC scrutinizes purchases under Rule 10b5-1 for material non-public information. Sales, by contrast, are often driven by liquidity, tax planning, or pre-scheduled 10b5-1 trading plans rather than negative information. Cluster buying (multiple insiders buying within a short window) is a stronger signal than isolated buys.

How do MPLX insider transactions affect options pricing?

Insider transaction data does not directly drive implied volatility, but Form 4 disclosures can move single-name IV if the size or timing is unusual (e.g. a large CEO buy ahead of an earnings window). Options markets price the marginal informational content; routine transactions under pre-scheduled plans are typically ignored. For event-driven options sizing, pair the insider transaction history with the upcoming earnings calendar.