Shares of Fortescue Metals Group Limited (ASX: FMG) have fallen 3.4% today, which is heavier than the falls experienced by rivals BHP Billiton Limited (ASX: BHP) and Rio Tinto Limited (ASX: RIO) thus far.

After the market closed yesterday afternoon, the miner provided investors with a brief update regarding its annual production. It said it had shipped 169.4 million tonnes (mt) during financial year 2016, which compares to its previous guidance of 165mt provided in February.

However, the miner has been expected to exceed that target since April when it announced that shipments were running ahead of target — an achievement that it attributed to mild weather experienced during the March quarter. At the time, it said “potential upside to the full year guidance remains subject to the impact of weather during the June quarter.”

It’s possible that investors had hoped for a greater guidance beat given how strongly the shares have risen recently.

Even with today’s decline, Fortescue’s shares have skyrocketed 127% since the beginning of the year and are currently trading near a two-year high as a result of a rebounding iron ore price, together with a strengthened balance sheet.

Thanks in large part to operational improvements, the miner has repaid a considerable amount of debt, including a US$500 million repayment in June which will generate interest savings of US$21 million per year.

Fortescue’s management team deserve recognition for their ability to steer the company through what has been a very tough period for the industry as a whole, but an investment in the miner is still not without risk.

According to The Metal Bulletin, iron ore is currently fetching around US$59 a tonne which many economists believe is unsustainable. Given Fortescue’s heavy reliance on the commodity for its revenue and earnings, a sharp fall in the iron ore price would not bode well for the miner or its shareholders.

Free Report: 3 Rotten Shares to Sell, and 1 to Buy Today

After a double-digit rally for the ASX since 2016 lows, investors should be on high alert. You'll find a full rundown below of 3 shares we think you should avoid today plus one top pick worth buying, even if the market turns south and the RBA keeps rates at an "emergency low." Simply click here to uncover these stocks.

HOT OFF THE PRESSES: Motley Fool’s #1 Dividend Pick for 2017!

With its shares up 155% in just the last five years, this ‘under the radar’ consumer favourite is both a hot growth stock AND our expert’s #1 dividend pick for 2017. Now we’re pulling back the curtain for you... And all you have to do to discover the name, code and a full analysis is enter your email below!

Simply enter your email now to receive your copy of our brand-new FREE report, “The Motley Fool’s Top Dividend Stock for 2017.”

By clicking this button, you agree to our Terms of Service and Privacy Policy. We will use your email address only to keep you informed about updates to our website and about other products and services we think might interest you. You can unsubscribe from Take Stock at anytime. Please refer to our https://www.fool.com.au/financial-services-guide">Financial Services Guide (FSG) for more information.

Motley Fool contributor Ryan Newman has no position in any stocks mentioned. The Motley Fool Australia has no position in any of the stocks mentioned. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Bruce Jackson.