In the last year, many Marathon Petroleum Corporation (NYSE:MPC) insiders sold a substantial stake in the company which may have sparked shareholders’ attention. When analyzing insider transactions, it is usually more valuable to know whether insiders are buying versus knowing if they are selling, as the latter sends an ambiguous message. However, when multiple insiders sell stock over a specific duration, shareholders should take notice as that could possibly be a red flag.

While we would never suggest that investors should base their decisions solely on what the directors of a company have been doing, we would consider it foolish to ignore insider transactions altogether.

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In the last twelve months, the biggest single sale by an insider was when the insider, Michael Henschen, sold US$1.1m worth of shares at a price of US$202 per share. That means that even when the share price was below the current price of US$214, an insider wanted to cash in some shares. As a general rule we consider it to be discouraging when insiders are selling below the current price, because it suggests they were happy with a lower valuation. Please do note, however, that sellers may have a variety of reasons for selling, so we don’t know for sure what they think of the stock price. This single sale was just 24% of Michael Henschen’s stake.

Marathon Petroleum insiders didn’t buy any shares over the last year. The chart below shows insider transactions (by companies and individuals) over the last year. By clicking on the graph below, you can see the precise details of each insider transaction!

Check out our latest analysis for Marathon Petroleum

insider-trading-volume

NYSE:MPC Insider Trading Volume April 21st 2026

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The last three months saw significant insider selling at Marathon Petroleum. Specifically, insiders ditched US$2.1m worth of shares in that time, and we didn’t record any purchases whatsoever. This may suggest that some insiders think that the shares are not cheap.

Many investors like to check how much of a company is owned by insiders. We usually like to see fairly high levels of insider ownership. Marathon Petroleum insiders own about US$117m worth of shares (which is 0.2% of the company). I like to see this level of insider ownership, because it increases the chances that management are thinking about the best interests of shareholders.

Insiders haven’t bought Marathon Petroleum stock in the last three months, but there was some selling. And even if we look at the last year, we didn’t see any purchases. But it is good to see that Marathon Petroleum is growing earnings. While insiders do own a lot of shares in the company (which is good), our analysis of their transactions doesn’t make us feel confident about the company. So while it’s helpful to know what insiders are doing in terms of buying or selling, it’s also helpful to know the risks that a particular company is facing. For example – Marathon Petroleum has 2 warning signs we think you should be aware of.

Of course, you might find a fantastic investment by looking elsewhere. So take a peek at this free list of interesting companies.

For the purposes of this article, insiders are those individuals who report their transactions to the relevant regulatory body. We currently account for open market transactions and private dispositions of direct interests only, but not derivative transactions or indirect interests.

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This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.