Here's what's behind the big copper pop

Trading the red-hot red metal

The red metal has been red-hot lately, rising 6.5 percent since the start of last week. In fact, copper has just enjoyed its best week since 2011.

Investors seem to be getting a bit less bearish about China, the world's biggest consumer of copper. On Friday, China's official purchasing managers' index showed mild growth in April, beating expectations. On the other hand, HSBC's April PMI came in at 48.9, indicating manufacturing contraction.

Read MoreChina's factory activity lowest in a year: HSBC final PMI

More help may have come from the recent retreat in the dollar index. Hard assets like copper tend to move inversely to the U.S. dollar, as a weaker greenback means that it takes more dollars to buy the same amount of copper.

The copper bounce has also breathed fresh life into copper-exposed stocks like Freeport-McMoRan. The mining company has seen its stock surge 14 percent since the start of last week.

Rodrigo Garrido | Reuters

However, copper and mining stocks haven't been huge winners this year. The rally over the past week has been just enough to bring copper up 3 percent in 2015. And traders say that short-covering could be driving the magnitude of the recent move.

"I'm looking for a pullback here, I think it's going to settle in a little bit," David Seaburg, head of equity sales trading at Cowen, said in an interview Friday. "I think this spike is really predicated mostly on dollar weakness and hedge-fund short-covering here."

While acknowledging the bullish activity on Freeport-McMoRan in the options market, Stacey Gilbert of Susquehanna said that "given the overall short of copper, I wouldn't be surprised if some of this is protection for a continued copper pop here."

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