It's been difficult for Americans to legally invest in the world's booming marijuana business but a new online fund will let you do it at the click of a mouse.

Canadians are bringing a new meaning to the term "investor high," with the world's first marijuana-focused exchange-traded fund opening on the Toronto Stock Exchange.

The Horizons Medical Marijuana Life Sciences exchange-traded fund is comprised of 14 stocks, allowing investors to diversify their risk. The fund uses the North American Medical Marijuana Index as a benchmark.