Freeport-McMoRan shares plunge after China reported disappointing trade data
A dump truck unloads ore into a crusher in the underground area at Freeport McMoRan's Grasberg copper and gold mining complex in Papua province, Indonesia.

Shares of Freeport-McMoRan plunged more than 4 percent Thursday after China reported disappointing trade data.

On Thursday, China's Customs Bureau said China's exports in September tumbled nearly 10 percent year-on-year in dollar-terms, and imports dipped 1.9 percent from the previous year.

Materials were one of the worst-performing sectors in the S&P 500 in afternoon trade Thursday. Copper was down 2.3 percent after falling more than 3 percent on session lows.

"China's September data for copper is pretty poor and fits in with the idea that although demand in China is not that bad, the country does seem to be going through a de-stocking phase," Oxford Economics commodity director Dan Smith told Reuters, adding that strong production is not supportive of higher prices in the short term.

Freeport-McMoRan is still up more than 42 percent year to date.