Image Source: Coeur Mining

What: Coeur Mining, (CDE -5.80%) advanced a heady 45% last month. It's up 120% so far this year and an astonishing 200% since the middle of January.

So what: Coeur Mining's share price rally has pretty much coincided with the run up in commodity prices since the middle of January. So, clearly, the upturn in precious metals prices have led investors to push this miner's shares higher in a big way. But that isn't a complete explanation here.

For example, Barrick Gold's (GOLD -7.05%) shares have rallied on higher precious metals prices, too. But they are "only" up about 80% since mid-January. Why is it that Coeur's shares have gone up more than twice as much? The answer is costs.

Coeur's cost to pull an ounce of silver out of the ground in 2015 was roughly $15.66 per ounce. Silver started this year at around $13.80 an ounce. Easy math will tell you that Coeur has a cost issue to deal with. Which is why the fact that silver has been moving higher has been such a huge benefit for Coeur, it's the difference between making money and, well, not. Silver ended March at around $15.20 an ounce.

Now compare that to Barrick, which manages to pull an ounce of gold out of the ground for less than the price it gets for the metal. Clearly, a precious metals upturn will help both miners, but it will help Coeur far more than Barrick. Which explains why investors have pushed Coeur's shares so far so fast compared to Barrick.

Now what: Coeur Mining is really more of a marginal player than a company like Barrick. In other words, it needs higher prices for it to really turn a profit. That said, the company has been working to reduce costs, but precious metals prices are still the key factor in whether or not Coeur makes money or loses money. (It's bled red ink in each of the last three years, just for reference.) Most investors would probably be better off with a miner like Barrick if they are looking for precious metals exposure. However, if you have a really strong feeling that precious metals are headed even higher, and a strong stomach, Coeur will likely give you more bang for the buck.