Recently, Cronos Group made history when they became the world's first plant-touching cannabis company to be listed on Nasdaq - a milestone for the industry.

According to a report on CNBC by Reuters’ Mark Blinch, it is the not the first time a cannabis-related company has been listed on a major U.S. exchange. In December, Alternative Harvest ETF, a fund that trades on the NYSE Arca, started investing in marijuana companies, giving investors access to a basket of marijuana stocks. By March, Alternative Harvest had increased its assets to more than $400 million. Cronos Group is included in that fund.

But with Cronos Group's listing on the Nasdaq, for the first time, investors can buy a specific cannabis stock. More cannabis companies are sure to follow, says Blinch.

Cronos Group operates cannabis cultivation and distribution operations in Australia, Canada, Germany, and Israel — countries in which medical marijuana is legal. The company’s stock is also traded in Canada and Germany.

Stock exchanges have stringent requirements for companies looking to list. Having broken federal laws is a deal breaker, Blinch points out. So, Canadian companies meet listing requirements because medical cannabis is legal in Canada. But U.S.-based growers cannot because cannabis is federally illegal. U.S. companies are also excluded from the Toronto Stock Exchange for the same reason.

"It is a significant signal that a major U.S. exchange does not have an issue with cannabis, but rather the U.S. federal status," said Hadley Ford, CEO of iAnthus Capital.

Public companies that cannot list on the major exchanges can, however, list on alternative exchanges. The U.S. over-the-counter exchanges and the Canadian Securities Exchange are examples. But these types of exchanges typically result in less access to major institutional investors, according to Blinch.

Being one of the first companies to list on Nasdaq has its advantages. For instance, it gives major investors around the globe access.

“The Canadian market may be getting a leg up over the U.S.,” says Blinch, “but most aren't overly concerned that Canada will leave its southern neighbor in the dust.”