Freeport McMoRan is getting slammed after China's disappointing data

Metal and mining stocks are getting hammered Thursday after after China reported disappointing trade data.

Among the worst performers, copper-producer Freeport McMoRan is off more than 7% while US Steel is down 5.6%.

Earlier Thursday, China's Customs Bureau said September exports tumbled by 10% in US dollar terms compared to a year ago. Economists had expected a much smaller 3% drop. Additionally, the bureau said that imports shrank by 1.9% YoY versus expectations of a 3% gain.

As a result of the weak export figure, the trade surplus narrowed to $41.99 billion, the narrowest seen since March.

A deeper dive within the data shows that steel exports fell to 8.8 million metric tons in September. That is down from 9 million tons in August and from the record 11.2 million tons from a year ago. While the customs bureau warned that it is seeing "intensified" trade protectionism, the story here appears to be one of demand.

And waning demand means bad news for the global economy, and bad news for economically sensitive stocks.

Investing.com