With just a month to go before we turn the page on 2018, it's pretty safe to say that it's been a record-breaking year for the marijuana industry.

To our north, Canada became the first industrialized country in the world to legalize recreational cannabis on Oct. 17. In doing so, Canada has set the blueprint for other industrialized countries to follow, as well as paved a path to billions of dollars in added annual sales for the legal weed industry within the country.

Then, in the U.S., we witnessed two new states legalize medical cannabis during midterm elections, with another, Michigan, voting to become the 10th state to OK adult-use pot. The U.S. Food and Drug Administration (FDA) also approved its very first cannabis-derived drug in June.

A cannabis leaf partially covering Ben Franklin's face on a hundred dollar bill, with his eyes visible between the leaves.

Image source: Getty Images.

These one dozen pot stocks are in the billion-dollar club

Add up these and many other milestones in 2018 and it's not hard to see why there are now a dozen pure-play marijuana stocks with at least a $1 billion market cap. Listed in descending order, here are the largest 12 publicly traded pot stocks.

1. Canopy Growth Corp.: $11.5 billion market cap

The kingpin of all marijuana stocks is currently Canopy Growth Corp. (NYSE:CGC), with a market cap of $11.5 billion. Canopy retook the crown recently after Corona and Modelo beer producer Constellation Brands purchased 104.5 million shares of Canopy's stock at a 51% premium to its Aug. 14 closing price. Now sporting more than $4 billion in cash and cash equivalents on its balance sheet following the closure of this investment, Canopy Growth has more than enough capital to expand production, lay the groundwork for international sales channels, build up its brands, diversify its product portfolio, and make acquisitions.

2. Tilray: $10.3 billion

Despite only going public in late July, bottle-rocket Tilray (NASDAQ:TLRY) caught fire in September and briefly had a market cap of almost $28 billion on an intraday basis. High borrowing costs for short sellers, along with the expectation that Tilray would find a partner in the beverage or tobacco industry, were the primary catalysts pushing its shares higher. In 2019, Tilray's management team will be focused on expanding its production capacity -- it has about 3 million square feet of land available for expansion -- and pushing into new international markets.

3. Aurora Cannabis: $5.9 billion

Although it's only third in total market cap, Aurora Cannabis (NYSE:ACB) is likely to lead the pack in terms of peak annual output at an author-estimated 700,000 kilograms, if not higher. Aurora has accomplished this via organic projects (Aurora Sky and Aurora Sun), through strategic partnerships (Aurora Nordic), and with the help of multiple big-name acquisitions (CanniMed Therapeutics, MedReleaf, and ICC Labs). If not for the massive dilutive impact of Aurora's numerous bought-deal offerings, it may have given Canopy Growth a run for its money as market-cap leader.

A GW Pharmaceuticals lab worker closely examining a beaker filled with a cannabinoid-rich liquid.

Image source: GW Pharmaceuticals.

4. GW Pharmaceuticals: $3.9 billion

The only pure-play cannabinoid drug developer on this list is GW Pharmaceuticals (NASDAQ:GWPH), with a market cap of nearly $4 billion. GW Pharmaceuticals made history in June when its lead drug, Epidiolex, was approved by the FDA to treat two rare forms of childhood-onset epilepsy after running circles around the placebo in pivotal-stage trials. GW Pharmaceuticals' cannabidiol (CBD)-based drug also received the least stringent scheduling of all from the U.S. Drug Enforcement Agency (Schedule V), which may pave the way to higher sales and CBD-scheduling reform at the federal level.

5. Curaleaf Holdings: $2.7 billion

Talk about coming out of nowhere! In late October, Curaleaf Holdings went public in what's now the largest marijuana initial public offering (IPO) in history. Though Curaleaf has shed some of its $4 billion-plus valuation from when it went public, the vertically integrated operator of 33 dispensaries, 12 cultivation facilities, and 10 processing sites (all of this in the U.S., might I add) clearly has investors' attention. Since interstate transport of cannabis isn't permitted under federal law, Curaleaf's involvement up and down its weed supply chain should help it control its costs and maximize margins.

6. Aphria: $2.1 billion

Ontario-based grower Aphria (NYSE:APHA) currently slots in as the sixth-largest pot stock, with a market cap of just over $2 billion. Aphria is expected to be the third-biggest grower by peak annual output at 255,000 kilograms, trailing only Aurora Cannabis and Canopy Growth. Its organically constructed Aphria One facility is expected to yield 100,000 kilograms a year, with Aphria Diamond -- a strategic partnership between Aphria and Double Diamond Farms that involves the retrofit of vegetable-growing greenhouses for cannabis production -- adding around 120,000 kilograms a year at its peak.

A large sign outside of a cannabis dispensary that reads, in big white letters, Marijuana.

Image source: Getty Images.

7. Green Thumb Industries: $1.7 billion

A common theme you'll notice with these largest market-cap marijuana stocks is that they're either growers or vertically integrated dispensaries like Green Thumb Industries. Green Thumb operated more than a dozen of its RISE retail cannabis stores at the end of its fiscal third quarter, which goes along with eight manufacturing facilities. Green Thumb has licenses to open 60 retail locations in eight markets, meaning it'll be spending aggressively in the next couple of years to boost its presence in those states. However, this figure could easily expand if U.S. states continue to give the green light to recreational weed. 

8. Cronos Group: $1.5 billion

Cronos Group (NASDAQ:CRON) is another grower that aims to be a top-10 producer when at peak capacity. The company essentially doubled its production capabilities in July when it announced a joint venture project with a group of investors that'll be known as Cronos GrowCo. This project involves the construction of an 850,000-square-foot facility capable of 70,000 kilograms of peak annual output. Also fanning Cronos Group's flames in 2018 was its uplisting to the Nasdaq exchange and its unique deal with Ginkgo Bioworks to develop low-cost cannabinoids at commercial scale using custom yeast strains.

9. MedMen Enterprises: $1.5 billion

Of all the U.S.-based, vertically integrated dispensary operators, MedMen Enterprises (NASDAQOTH:MMNFF) might be the best known. MedMen aims to normalize the cannabis-buying experience -- and it seems to be working, with its dispensaries registering higher sales per square foot than Apple stores. MedMen currently has 14 operating stores and five cultivation sites, but is in the process of acquiring privately held PharmaCann for $682 million. This'll add 18 new retail locations and eight cultivation sites, and double its presence to 12 states.

A cannabis processor holding a freshly trimmed bud in their gloved left hand.

Image source: Getty Images.

10. Acreage Holdings: $1.2 billion

Another big name that just recently went public is diversified cannabis company Acreage Holdings. For those who may not know, former Speaker of the House John Boehner, former Massachusetts Gov. Bill Weld, and former Canadian Prime Minister Brian Mulroney are all part of Acreage's board of directors. Acreage has plans to use its capital to enter new U.S. markets as its management and board see fit. This might include pot production, cannabis processing, financing existing operations, or running retail dispensaries. 

11. Charlotte's Web Holdings: $1.2 billion

Charlotte's Web Holdings is another in a long line of pot stocks that recently went public. Charlotte's Web is a producer and distributor of hemp-based CBD products in more than 3,000 retail locations in the United States. The company has gained quick notoriety among investors since CBD products aren't as tightly regulated as dried cannabis. Charlotte's Web's exposure to more than 3,000 retail locations has allowed it to generate $48 million in sales through the first nine months of 2018, to go along with an $8.7 million profit. 

12. Trulieve Cannabis: $1.1 billion

The 12th and final billion-dollar marijuana stock is Trulieve Cannabis. Trulieve recently opened its 22nd dispensary in Florida's fast-growing medical marijuana market. Though Florida's not the oldest state by average age, its friendly tax laws and warm climate make it a common destination for retirees -- and older Americans are more likely to have ailments that medical marijuana or CBD might help. Last month, Trulieve also purchased companies in California and Massachusetts, marking its entrance into two new markets. 

Sean Williams has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Apple. The Motley Fool has the following options: long January 2020 $150 calls on Apple and short January 2020 $155 calls on Apple. The Motley Fool recommends Constellation Brands and Nasdaq. The Motley Fool has a disclosure policy.