What happened

Shares of copper and gold miner Freeport-McMoRan (NYSE:FCX) rose just shy of 11% in October, according to data from S&P Global Market Intelligence. Performance, however, didn't go in a straight line across the month. In fact, the stock was up by 17% at one point, just after the company reported earnings. But over the last week of the month the stock headed lower, giving back a portion of its gains.  

So what

It would be easy to suggest that earnings were the problem, but the numbers were actually pretty solid. For example, year-over-year revenues were higher by 22% in the third quarter, with earnings coming in at $0.22 per share up from a loss of $0.15 per share in the same quarter of 2019. That said, the improved performance was largely attributable to increased selling prices for copper and gold, higher by 15% and 28%, respectively. Production of both copper and gold was lower year over year, though the company actually sold more copper in the third quarter of 2020 than it did in the same period of 2019. On the whole, Freeport-McMoRan appears to have had a decent third quarter. So why did the stock start to fall after the company reported results?   

A large collection of copper pipes sitting on their ends.

Image source: Getty Images.

The answer is pretty simple and goes right back to the heart of Freeport-McMoRan's business -- it's a miner that sells often volatile commodities. The biggest impact on its business is copper. Copper rose through most of October, but started to head lower over roughly the last week of the month. There's not a lot the miner can do about its relationship with the metals it produces. Investors will always see it as a proxy for copper, and its shares will always trade generally in line with that key industrial metal. In other words, there were no surprises in October for Freeport-McMoRan or its shareholders. The stock did exactly what you'd expect given the price moves in copper.

Now what

Freeport-McMoRan is one of the world's largest copper miners -- if you are looking to invest in this metal, it needs to be on your short list. However, one month's gain (or loss) isn't really the most important thing you need to consider here, since the stock is likely to track along with the prices of the main commodity it produces. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.