Let's face it: Aurora Cannabis (ACB -0.95%) and Canopy Growth (CGC -1.96%) are pretty much in a league of their own among marijuana stocks. They have the biggest market caps, the highest production capacities, and the most significant international operations.

Which smaller Canadian marijuana stock has the best shot at joining the ranks with these top-tier players? By smaller, I'm referring to small-cap stocks with market caps of less than $2 billion, which excludes Cronos Group and Tilray from consideration.

The three obvious candidates are Aphria (APHA), Organigram (OGI -1.22%), and HEXO (HEXO). Here's why these companies seem to have the best chances of joining Aurora and Canopy at the top of the pack. 

Shadow of a dollar sign on top of a pile of marijuana leaves

Image source: Getty Images.

1. Aphria

My view is that Aphria is the most likely smaller marijuana stock to make the big leap. Actually, I think that Aphria probably has the most upside potential of any of the Canadian marijuana producers with $1 billion or higher market caps for several reasons.

Aphria ranks in third place behind Aurora and Canopy in terms of production capacity. It can produce 115,000 kilograms on an annual basis currently and is on track to boost its capacity to around 255,000 kilograms annually by the end of this year. 

The company also has a solid international presence already -- and it's in global markets where the greater long-term growth potential lies. Aphria was, along with Aurora, one of three companies to win approval to cultivate medical cannabis in Germany. It's in a strong position to reach the rest of Europe and is positioned well in Australia and Latin America, too.

These attributes combined with Aphria's relatively attractive valuation could make the company a prime candidate for partnering with major players outside of the cannabis industry. Landing the right partner just might catapult Aphria into the top tier. 

2. Organigram

Organigram is beating Aurora, Canopy Growth, and nearly every other Canadian marijuana stock in one key arena -- stock performance. Its share price enjoyed a nice bounce from the approval to be listed on the Nasdaq stock exchange. This is a big step for Organigram since it was behind many of its peers in listing its shares on a U.S. exchange.

The company is no slouch when it comes to production capacity. Organigram is on course to have an annualized production capacity of 113,000 kilograms by the end of this year. 

Although Organigram is smaller than Aurora and Canopy, it claims supply agreements with nine provinces and a signed letter of intent with Quebec that would give the company a presence in all of Canada's provinces. It's also in great shape for the Canadian cannabis edibles market that is scheduled to open later this year. And the company has a launching pad in Europe with its collaborations with Alpha-cannabis in Germany and Serbian hemp producer Eviana.

Like Aphria, Organigram doesn't have a big partner outside of the cannabis industry. But the company's low production costs, industry-leading gross margins, and overall potential could catch the attention of some major players in the alcoholic beverages, consumer packaged goods, and/or tobacco industries.

3. HEXO

HEXO is sort of the oddball of the three smaller marijuana stocks that could join the ranks of Aurora and Canopy Growth. The company already has a key partnership with Molson Coors Brewing to develop cannabis-infused beverages.

In addition, HEXO is a favorite of at least one Wall Street analyst. Bank of America's Christopher Carey likes the company's partnership with Molson Coors but especially views HEXO's position in the adult-use recreational marijuana market in Quebec, Canada's second-largest province in terms of population.

Last year, HEXO scored a massive supply agreement with Quebec. The deal gives the company a market share of at least 30% for the next few years. HEXO should have ample capacity to serve the market as it's on track to produce 150,000 kilograms of cannabis per year. 

One key for HEXO to vault into the upper echelon of Canadian marijuana stocks is to increase its international presence. The company has a start with its partnership with Greek cannabis operator Qannabos. HEXO could also line up additional big partners, the company's preferred strategy to entering the U.S. hemp market.

Easier said than done

I think that Aphria has the best shot at moving up to the big league with Aurora Cannabis and Canopy Growth, but I wouldn't dismiss the possibility that either Organigram or HEXO could get there sooner. However, it's certainly not a foregone conclusion that any of these companies will become top-tier players.

Canopy Growth's cash from its deal with Constellation Brands and the relationship with the big alcoholic beverage maker gives the company a major advantage that could be sustainable over the long run. Aurora is taking a different partnership path by seeking deals that don't involve equity stakes, but it's one that could make the company even more formidable in the future.

Once companies establish a gap between themselves and the rest of the field, it's hard for others to close the distance. If any smaller marijuana producers can do it, I suspect that it will be either Aphria, Organigram, or HEXO. But jumping into the top ranks is easier said than done.