Over the past year, many Martin Marietta Materials, Inc. (NYSE:MLM) insiders sold a significant stake in the company which may have piqued investors' interest. Knowing whether insiders are buying is usually more helpful when evaluating insider transactions, as insider selling can have various explanations. However, when multiple insiders sell stock over a specific duration, shareholders should take notice as that could possibly be a red flag.

Although we don't think shareholders should simply follow insider transactions, we do think it is perfectly logical to keep tabs on what insiders are doing.

View our latest analysis for Martin Marietta Materials

The Last 12 Months Of Insider Transactions At Martin Marietta Materials

Over the last year, we can see that the biggest insider sale was by the Chairman, C. Nye, for US$12m worth of shares, at about US$604 per share. That means that an insider was selling shares at around the current price of US$557. While we don't usually like to see insider selling, it's more concerning if the sales take place at a lower price. Given that the sale took place at around current prices, it makes us a little cautious but is hardly a major concern.

In the last year Martin Marietta Materials insiders didn't buy any company stock. 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!

I will like Martin Marietta Materials better if I see some big insider buys. While we wait, check out this free list of undervalued and small cap stocks with considerable, recent, insider buying.

Does Martin Marietta Materials Boast High Insider Ownership?

I like to look at how many shares insiders own in a company, to help inform my view of how aligned they are with insiders. We usually like to see fairly high levels of insider ownership. Martin Marietta Materials insiders own about US$219m worth of shares (which is 0.6% of the company). Most shareholders would be happy to see this sort of insider ownership, since it suggests that management incentives are well aligned with other shareholders.

So What Does This Data Suggest About Martin Marietta Materials Insiders?

The fact that there have been no Martin Marietta Materials insider transactions recently certainly doesn't bother us. It's heartening that insiders own plenty of stock, but we'd like to see more insider buying, since the last year of Martin Marietta Materials insider transactions don't fill us with confidence. So these insider transactions can help us build a thesis about the stock, but it's also worthwhile knowing the risks facing this company. Be aware that Martin Marietta Materials is showing 3 warning signs in our investment analysis, and 1 of those is significant...

Of course Martin Marietta Materials may not be the best stock to buy. So you may wish to see this free collection of high quality 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.

Have feedback on this article? Concerned about the content? Get in touch with us directly. Alternatively, email editorial-team (at) simplywallst.com.

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.