Pentagon-backed MP Materials warned investors this week to approach other rare earths projects with caution, pointing to the industry’s difficult economics.

Stocks of U.S. rare earth companies have had wild swings in recent months as investors have speculated that the Trump administration might strike more deals along the lines of its landmark agreement with MP. Smaller retail traders have gotten involved in the stocks with the VanEck Rare Earth and Strategic Metals ETF up 60% this year.

The Defense Department in July took an equity stake in MP, set a price floor for the company, and inked an offtake agreement with the rare earth miner and magnet maker in an effort to roll back China’s dominance of the industry.

CEO James Litinsky said he didn’t want “people to get burned” amid the speculation. Litinsky cautioned investors “to just be very clear-eyed about what the actual structural economics are amidst all the excitement.”

“The vast majority of projects being promoted today simply will not work at virtually any price,” Litinksy said on the company’s third-quarter earnings call Thursday evening.

MP views itself as “America’s national champion,” Litinsky said. MP is the only active rare earth miner in the U.S. and has offtake agreements with Apple and General Motors in addition to the Pentagon.

“We have structural advantage because we’re fully vertically integrated,” the CEO said. “We’re years and billions ahead of others.”

It takes years for the best rare earth producers to ramp up and stabilize their output and economics “despite what some promoters might suggest,” Litinksy said. Australia’s Lynas took about a decade and MP will reach normalized production in about three years from the start of commissioning, he said.

The White House is “not ruling out other deals with equity stakes or price floors as we did with MP Materials, but that doesn’t mean every initiative we take would be in the shape of the MP deal,” a Trump administration official told CNBC in September.

Litinsky described the rare earth industry as close to a “structural oligopoly,” a system where there are just a few major players. The government investing in a dozens of sites and businesses wouldn’t necessarily set up a supply chain, he said.

The Trump administration should continue to encourage private capital to flow into the industry through loans, grants and other support, Litinsky said. There is room for “a lot of other players and supply” but the market will require “materially higher prices” for the industry’s structural challenges to change, he said.

“If X dollars of capital can stimulate two or three X in private capital, they should be doing that as much as possible,” Litinsky said.

The CEO indicated that he views MP as a forerunner that will help create the conditions for a broader market that is not dependent on China over time.

“In the very short term the administration has made sure that we have a successful national champion in MP,” Litinsky said. “We are going to sort of pave the path if you will to then figure out how there’s much broader supply coming online.”

Rare earths are crucial for making magnets that are key inputs in U.S. weapons platforms, semiconductor manufacturing, electric vehicles, clean energy technology and consumer electronics. Beijing dominates the global supply chain and the U.S. is dependent on China for imports.