If you invested $10,000 in 3M (MMM 0.16%) a decade ago, it would be worth roughly $9,900 today. If you only look at the starting point and ending point, you might conclude that 3M has done a lot of nothing over that 10-year time span.

That, however, is not true at all. Here's a closer look at what's behind the numbers and why conservative investors might want to tread with caution around this industrial stock.

Start to finish

The first thing to note in the performance previously mentioned is that it is for the stock price only. 3M pays a dividend and has increased it every year for over six decades, making the industrial icon a highly elite Dividend King. When you include dividend reinvestment into the picture, which is the total return, that $10,000 investment would have turned into $13,300.

While that's a much better number, an S&P 500 index ETF would have turned that $10,000 into $26,000 or so on a stock price-only basis, and over $31,000 with dividend reinvestment.

MMM Chart

MMM data by YCharts

Pretty clearly, 3M has not been a winner for investors. But the chart shows that the past decade has been one heck of a ride for 3M shareholders. In 2018, at the most recent high-water mark for the stock, the value of that $10,000 peaked at around $24,000 -- far above what the S&P had achieved at that point in time. But then the shares went into a multiyear downtrend.

At this point, the sell-off has pushed the stock's dividend yield up to 5.7% or so. That's the highest level the yield has been in decades. In fact, the yield is even higher today than it was during the Great Recession. While that suggests that the stock is cheap today, it also highlights the fact that something big is going on.

MMM Chart

MMM data by YCharts

Headwinds galore

Industrial stocks, including 3M, tend to be cyclical, so the company will periodically deal with economic headwinds in its business (as it faces now). Inflation is another factor that's causing problems, as the company's profit margins are under pressure. But these are the same types of things that all industrial companies are facing right now. It's a problem, but it hardly explains why the stock has been so unloved. The real story here is company specific. 

For starters, 3M's growth is a bit anemic of late. Revenue growth expanded at a compound annual rate of just 1.4% over the past decade. That's not particularly impressive, even for a company that's only expected to grow along with economic expansion, which is normally in the low single digits. Management has been buying and selling businesses to try to shift into a higher gear, but so far, that hasn't played out particularly well.

Then there are the product liability lawsuits surrounding earplugs the company sold to the U.S. armed forces, as well as the legal and regulatory issues with forever chemicals. Both of these problems have been very expensive to deal with, are far from over, and could involve material legal costs to settle. This pair of topics also goes a long way toward explaining the steep stock price decline since 2018.

But there's more to worry about here. 3M has now decided to shutter the division that made forever chemicals. That's another multiyear effort and a big expense. It is also looking to spin off its healthcare division, which was expected to be the company's main growth engine in the future. That's a worrying statement, since it suggests that management is trying to protect its crown jewels in a move that could stifle future growth at 3M.

Adding to the uncertainty there, meanwhile, is the dividend risk that comes with a large spinoff. It wouldn't be shocking if 3M "right-sized" its dividend at the same time that investors got shares in the stand-alone healthcare business. No wonder investors are worried about 3M stock.

No quick solutions

There's no reason to believe that any of the company's legal issues are going to end soon. The spinoff of the healthcare division will happen in relatively short order, but that will simply increase the risk associated with the businesses left behind.

At this point, only aggressive investors should be looking at 3M. It's highly likely that a $10,000 investment today won't be particularly profitable over the next few years, if not longer.