Commodity producers have been tightening their belts and cutting back, leading to a prolonged period of underinvestment and potentially fueling higher prices in raw materials and related exchange traded products ahead.

Portfolio managers project that the price of copper, nickel and aluminum could surge past prior records, or over 40% current levels, in the coming years, the Wall Street Journal reports.

After an extended period where commodity producers have not expanded into new projects and mining sites, the dwindling supply could push up prices. In the mean time, investors may benefit through metals-related ETPs like the iPath Bloomberg Copper Subindex Total Return ETN (NYSEArca: JJCTF), United States Copper Index Fund (NYSEARCA: CPER), iPath Bloomberg Copper Subindex Total Return ETN (NYSEArca: JJCB), iPath Series B Bloomberg Aluminum Subindex Total Return ETN (NYSEArca: JJUB) and iPath Series B Bloomberg Nickel Subindex Total Return ETN (NYSEArca: BJJN).

Global miners are only investing a third of what they did five years ago on new projects as they are on pace to invest roughly $40 billion for the third straight year, or down more than $120 billion five years ago and $80 billion almost a decade ago, according to Wood Mackenzie.

Christopher LaFemina, a mining analyst at Jefferies, argued that copper miners will need to spend an additional $50 billion in the next decade to balance the market. However, these companies are only spending about $10 billion a year.

“It’s incredibly bullish and inflationary for metals on a long enough horizon,” Stephen Gill, managing partner of Pala Investments, told the WSJ. “You have a window of opportunity at these low prices.”

Investors can pick up metals on the cheap. Commodities markets have been weakened on concerns that the U.S. and China trade war dispute will slow global growth and hurt demand, with base metals prices hovering in bear market territory.

Metals producers are similarly wary of spending in an uncertain trade environment.

“We’re not going to start investments until we have clarity about the ultimate outcome of all these current uncertainties,” CEO Richard Adkerson said on an October earnings call.

The lack of investments in the metals space could mirror what occurred previously in the oil market. Back in 2015 and 2016, a 25% plunge in spending on new projects helped contribute to the rally that sent crude prices to a near four-year high this year.

For more information on the commodities market, visit our commodity ETFs category.