The marijuana industry is growing like a weed in North America. ArcView, one of the leading cannabis research firms, has suggested that legal weed could grow by 26% on an annual basis between 2016 and 2021, leading to nearly $22 billion in annual sales. Even with regulatory restrictions, there's presumably a lot of money to made, which is why investors have piled into marijuana stocks and pushed their valuations substantially higher.

Of course, no two cannabis markets are alike. For instance, even though U.S. legal weed sale are expected to soar in 2018 as a result of California opening its doors to adult-use sales, the environment isn't conducive to investor success. The federal government has dug in its heels and refused to budge on its Schedule I classification -- this means pot is wholly illegal, prone to abuse, and has no recognized medical benefits -- and Attorney General Jeff Sessions is effectively waging war on the industry.

A jar of cannabis buds lying on a small stack of cash.

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Meanwhile, Canada is leading the charge in pot progressivism. Canada legalized medical cannabis back in 2001, and it's on track to possibly legalize the sale of recreational pot to adults by this summer. Doing so would make Canada only the second country in the world, behind Uruguay, to have legalized recreational marijuana. It'd also add billions in annual revenue for growers and other cannabis companies along the supply chain.

These pot stocks should be generating the most annual revenue by 2019

Which Canadian marijuana stocks stand to rake in the most revenue? That's a question for Wall Street. Mind you, Wall Street's sales estimates for Canadian pot stocks are absolutely all over the map. In some instances, the high estimate for fiscal 2019 is double that of the low estimate. The reason for this wild divergence is that there's simply no precedent for a burgeoning pot industry, so Wall Street is left to guess almost as much as retail investors.

But assuming analysts are remotely in the ballpark, the following five companies are set to rake in the highest estimated sales come 2019.

An indoor cannabis grow farm.

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1. Aurora Cannabis: $304.8 million

In terms of total sales, Aurora Cannabis (NASDAQOTH:ACBFF) may be the likeliest to breach $300 million in 2019, per Wall Street estimates. Keep in mind that the above revenue figure includes an estimated $110 million in annual sales from CanniMed Therapeutics (NASDAQOTH:CMMDF), which agreed to be acquired by Aurora Cannabis in January for $852 million, the priciest pot acquisition of all time. The CanniMed transaction adds 20,000 new medical patients to Aurora's network, along with 19,000 kilograms in funded capacity.

By 2019, Aurora Cannabis should be ready to deliver between 240,000 kilograms and 270,000 kilograms of cannabis, depending on approvals from Health Canada. This includes more than 100,000 kilograms from its state-of-the-art Aurora Sky facility, as well as its joint venture partnership with Alfred Pedersen & Son in Denmark, known as Aurora Nordic, that'll yield around 120,000 kilograms a year. 

Jars of dried cannabis stacked on one another.

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2. Canopy Growth Corp.: $251.2 million

Though Canopy Growth Corp. (NYSE:CGC) is second in projected sales in 2019, it's by far the biggest wildcard of the bunch. According to the high estimate from Wall Street, Canopy Growth could generate more than $393 million in sales, under the right conditions. Even with Aurora's acquisition of CanniMed Therapeutics, that'd push Aurora to No. 2.

According to Canopy Growth's latest operating results, it has a whopping 3.7 million square feet of greenhouse facilities under construction or in development in British Columbia. It also has a massive vertical channel of well-known brands, retail locations, and distribution partners that gives it substantive advantages over its peers. This is why most analysts agree that Canopy Growth will have the highest recreational and medical market share in Canada of any grower. 

An indoor commercial cannabis grow facility.

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3. Aphria: $146.2 million + Nuuvera acquisition

Next in line appears to be Aphria (NASDAQOTH:APHQF), albeit this is where some added "guesstimating" comes into effect. On the surface, Aphria looks to generate about 230,000 kilograms of cannabis by 2019. This comes from its $100 million-plus, four-phase flagship project, which will generate 100,000 kilograms annually, as well as its joint venture with Double Diamond Farms, which should produce 120,000 kilograms of cannabis a year. Its acquisition of Broken Coast Cannabis will add another 10,500 kilograms. All told, this is expected to yield around $146 million in sales in 2019.

However, it doesn't include the $670 million deal Aphria announced in January to acquire Nuuvera (NASDAQOTH:NUUVF). Nuuvera doesn't bring a lot of new production into the mix, but it does increase Aphria's reach to 11 total countries. This improved distribution network will be worth something, but with no Wall Street estimates at present, it's tough to quantify. My guess would be for total sales of around $170 million to $175 million in 2019. 

A cannabis bud lying atop a messy pile of $100 bills.

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4. Cannabis Wheaton Income Corp.: About $150 million

Cannabis Wheaton Income Corp. (NASDAQOTH:CBWTF) is also a major wildcard, because there are no Wall Street sales estimates on this relatively new weed-based royalty stock. Rather than building and maintaining greenhouse facilities, Cannabis Wheaton acts as something of a silent partner. It provides up-front capital to small, medium, and large growers looking to expand, and in return receives a percentage of their crop at a well-below market cost. Cannabis Wheaton then sells this product at market rates, pocketing the difference as profit.

With approximately 15 deals under its belt from all across Canada, Cannabis Wheaton estimated fairly recently that it could put 230,000 kilograms of marijuana on the market for sale in 2019. That would place it close to, but perhaps a tiny bit behind, Aphria, once Nuuvera is included in total production. While it's unclear what sort of product mix we'd be looking at (e.g., dried cannabis vs. oils), I'd estimate around $150 million in annual sales. 

A small vial of cannabis oil next to a cannabis leaf.

Image source: Getty Images.

5. MedReleaf: $119.3 million

Last but not least, MedReleaf (NASDAQOTH:MEDFF) is expected to generate a little bit over $119 million in annual sales. MedReleaf, which went public in 2017 and has used its initial public offering proceeds to expand its Bradford, Ontario, facility, should begin reaping the rewards of that expansion in 2019. When complete, Bradford will tout approximately 210,000 square feet in dedicated grow space, which should become its new flagship grow farm, displacing its Markham facility.

MedReleaf may not be selling as much dried cannabis as its peers, but it's definitely invested in its extracts and oils business. At the end of 2016, it controlled almost 45% of the cannabis oils market in Canada. Though that figure has likely slipped as new entrants have hit the market, the company has still stuck with oils as a higher-price and higher-margin product. 

You can probably expect these sales estimates to change substantially in the months to come, but these are, for now, your marijuana sale kingpins in Canada.

Sean Williams has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.