An investment company is making plans to launch what could be the first exchange-traded fund to profit on marijuana.

The Emerging AgroSphere ETF would give investors an opportunity to buy a group of companies making prescription drugs using cannabis extracts, selling hemp derivatives and other related stocks, fund backer ETF Managers Group LLC said in a filing with the U.S. Securities and Exchange Commission last week.

More than two dozen U.S. states have legalized some form of marijuana for medical or recreational use, though the drug remains illegal at the federal level.

Support for legalization of marijuana has risen to nearly 60 percent among U.S. adults, the Pew Research Center said last year. Ten years ago, just 32 percent of adults favored legalization, while 60 percent were opposed to it.

The investment company did not disclose a ticker symbol, its fees or a launch date but said the fund will be listed on NYSE Arca. A spokesman for ETF Managers Group LLC declined to comment.

Legal cannabis spending could rise to $21.6-billion in 2021, from $6.9 billion last year, according to the Arcview Group LLC, an investment and research company.

The ETF, which would buy stocks globally, “will not invest in any companies that are focused on serving the non-medical marijuana market in the United States, Canada or any other country unless and until such time as the production and sale of non-medical marijuana becomes legal in the United States, Canada or such other country,” the prospective fund’s managers said in the filing.