A slowing global economy is sending skittish investors out of industrial metals-related exchange traded funds at the fastest clip in over a year.

The PowerShares DB Base Metals Fund (NYSEArca: DBB), which tries to evenly split its portfolio with aluminum, copper and zinc futures, now has $279.7 million in assets under management after seeing $53.4 million in net outflows so far this month, according to ETF.com data.

Meanwhile, the iPath Dow Jones-UBS Copper Subindex Total Return ETN (NYSEArca: JJC), an exchange traded note that tracks coppers futures and holds $63.5 million in assets, experienced $1.8 million in outflows.

Nevertheless, industrial metals have been gaining over the past month, with DBB up 1.1% and JJC 1.0% higher. Despite the gains, the recent outflows suggest that investors are growing pessimistic over the future outlook for demand due to a weakening global economy.

U.S. exchange traded products, which include both ETFs and ETNs, that track industrial metals experienced $55 million in outflows over October, the most since July 2013, Bloomberg reports.

Hedge funds have bets on lower copper prices for five weeks, the longest period since April. Meanwhile, London Metal Exchange open interest on zinc futures is the lowest in 19 months while open interest on aluminum is down 10%.

“You’re seeing a panic exodus out of those ETFs,” Justin Holland, the managing director of metals trading at BNP Paribas in New York, said in a telephone interview Oct. 28. “The world was going along really nicely, and then all of a sudden, we had a bit of a hiccup because China’s numbers were coming in weaker than expected.”