“Cannabis is the next great American industry,” says Troy Dayton. As CEO of Arcview Group, Dayton works with over 650 high-net-worth investors who have poured more than $100 million into cannabis-related startups since 2010.

He calls early investors in the burgeoning marijuana industry “pioneers” who are hoping to stake their claims in the Green Rush.

Revenues from the US marijuana industry are expected to mushroom from $6.7 billion in 2016 to over $21 billion by 2021, according to Arcview Group research. Dayton predicts that explosive growth will happen, whether or not President Trump cracks down on legalized marijuana.

“[A crackdown] may impact valuations of some companies, and it may affect who invests in those companies, but states will continue to give out licenses, and there will be a line of people outside those facilities looking to purchase [the product].”

Twenty-eight states and the District of Columbia currently have laws legalizing marijuana in some form.

Next year is expected to be a particularly big year for the weed business because at least eight of the 11 states that passed medical or recreational cannabis laws in 2016 will begin selling it. So, in 2018, one in five Americans will live in an area where it’s legal to get high.

In addition, Canada is expected to legalize marijuana for recreational use on July 1, 2018. That’s expected to result in tens of billions of dollars in additional annual revenue for the cannabis sector, creating jobs and more business opportunities.

It appears there will be plenty of investors wanting in on the action. In an exclusive Yahoo News/Marist Poll, nearly three in 10 Americans (28%) say if cannabis were legal, they would like to invest in the marijuana business, including 21 % of non-users.

The poll also finds a majority of Americans approve of their bank (52%) or retirement fund (51%) investing in the marijuana industry.

Perhaps not surprisingly, the survey also finds there is a “generational divide” when it comes to people’s attitudes about investing in the cannabis sector. Overall, younger respondents feel more comfortable investing in the space. The poll shows 38% of millennials, 35% of Gen X, 21% of baby boomers, and only 6% of those 70 and older would be open to investing in the marijuana sector.

But Dayton tells Yahoo Finance that he sees a softening of this generation gap in his own business. “We see a lot of father-son, daughter-mother type matchups where the children have gotten the parents excited about the business side of marijuana, even though [the kids] were getting in trouble for smoking it just a few years ago.”

Banking on weed

While most large, mainstream banks still don’t do business with cannabis companies, they do recognize that their clients are interested in exploring weed as a viable investment opportunity.

In March, Bank of America held a panel about investing in cannabis as part of its annual Global Research Consumer Conference. Forty institutional investors attended the panel, though the bank declined to name the attendees.

And the brokerage firm Cowen & Co. held an event in January for its institutional investors interested in exploring opportunities in the marijuana space. Cowen also released an extensive report on the cannabis industry, suggesting the US recreational market could grow to $50 billion in annual revenues by 2026.

Overall, however, the financial industry has yet to catch up with marijuana’s increasing popularity. The fact that the drug is federally illegal in the US has many large banks and corporations keeping their distance.

Just over 300 smaller, regional banks, including Safe Harbor bank in Colorado, are currently doing business with the cannabis industry. That’s less than 3% of the nation’s 11,954 federally regulated banks and credit unions.

“We have to end federal prohibition of marijuana,” says Dayton. Once that happens, he says, bank resources and venture capital funds will flood the market.

The Green Rush

Dayton equates the legalization of marijuana to pivotal events in world history, such as President Richard Nixon normalizing relations with Communist China and the fall of the Berlin Wall. As with those historic events, Dayton says, “The desire to do business was already there, but laws were the impediments.”

In the meantime, many large companies are choosing to wager on the marijuana boom from afar. They are investing in ancillary industries, such as agriculture or consumption paraphernalia.

Scotts Miracle-Gro Co. saw its stock climb 48% last year. The fertilizer company also sells lighting and other supplies for hydroponics, an indoor method of growing cannabis.

Dayton describes investor events at Arcview Group as the “Shark Tank” of the cannabis industry. He adds that the Green Rush appears to cross party lines, with people from the right and the left interested in weed.

“Cannabis is one of the few things bringing America together these days.”