Last week, Horizons ETF Management launched the first medical marijuana exchange-traded fund ever to be approved by stock market regulators. The Medical Marijuana Life Sciences ETF is an investment fund that tracks companies involved with medical marijuana bioengineering, while avoiding any companies that are connected to recreational use.

The fund has seen immediate popularity, with an average daily trading volume of over a million shares. In the first four sessions since its launch, the fund rose a total of 17.8% in value, and has now amassed over $28 million in assets. This degree of success for a brand new fund is rare, and shows that there is a strong demand for investments in medical marijuana. The Horizons fund has occupied an unusual niche in the ETF market, as it tracks an industry that has seen heavy demand but did not previously have a publicly-traded fund due to the federal prohibition of marijuana.

A similar fund, the Emerging AgroSphere ETF, has also recently filed with the Securities and Exchange Commission. The filing states that the fund “will not invest in any companies that are focused on serving the nonmedical marijuana market in the United States, Canada or any other country unless and until such time as the production and sale of nonmedical marijuana becomes legal in the United States, Canada or such other country, respectively.”