Canopy Growth (NYSE:CGC) shares skyrocketed following news that it plans on entering the U.S. hemp market, and that has investors scrambling to figure out which pot stock could be next to deliver marketing-beating returns. The marijuana market is worth $150 billion annually, according to the United Nations, so the top cannabis companies could enjoy remarkable growth as marijuana prohibition lessens worldwide.

Although there are plenty of companies jockeying for market share in this emerging industry, CannTrust(NASDAQOTH:CNTTF) is my favorite marijuana stock to buy now. Is this stock right for your portfolio, too? Read on to learn how surging production and sales could make this stock a top performer in 2019.

A market up for grabs

The marijuana market is massive. In Canada, sales total about $6 billion Canadian annually. In the U.S., people spend an estimated $50 billion every year. The potential to tap into these markets has already resulted in a flurry of investment from the biggest marijuana companies, including Canopy Growth.

However, Canopy Growth is far from the only company that's likely to enjoy significant sales growth over the coming decade.

If they execute on their plans successfully, smaller marijuana companies, including Aphria (NYSE:APHA), Cronos Group(NASDAQ:CRON), Tilray (NASDAQ:TLRY), and CannTrust could also be big winners.

Aphria's targeting annual production north of 250,000 kilograms, Cronos Group is flush with financial firepower following a $1.8 billion investment from tobacco Goliath Altria(NYSE:MO), and Tilray's collaboration on marijuana medicine with biopharma giant Novartis make each of them interesting investment ideas. However, all three of those stocks come with reasons investors might not want to jump in and buy right now:

• Aphria needs to earn investors' trust back following allegations of self-dealing by executives last year.
• Shares of Cronos Group have already skyrocketed following the company's deal with Altria. 
• Tilray's notorious volatility makes it bests suited only for investors with iron stomachs.

By comparison, buying CannTrust now makes more sense. It's arguably the most overlooked of these potential top-tier pot-market participants. As a result, its $770 million market cap means it offers investors the lowest price-to-sales ratio of the bunch.

CannTrust's business is underappreciated

Given the multibillion-dollar market caps investors have awarded Aphria, Cronos Group, and Tilray, you might think their businesses are a lot bigger than CannTrust. But that's simply not true.

CannTrust's sales totaled CA$12.6 million in its most recently reported quarter of Q3 2018. In that same quarter, Tilray's sales were CA$12.9 million, and Cronos Group's sales were just CA$3.9 million. Aphria's fiscal calendar is different, but its sales were CA$13.3 million in the quarter ended August 2018, so CannTrust is competitive with it, too.

CannTrust's growth rate also matches up to them nicely. In Q3, CannTrust's sales jumped 105% year over year. That was better than the growth Tilray and Aphria reported, and although Cronos Group's 186% growth was higher than CannTrust's, Cronos Group's increase was off of a much smaller base.  

Also, CannTrust's been turning a profit, and that's no easy feat, given that every marijuana company is plowing big money back into their business for future growth. In Q3, CannTrust reported $421,240 in net income, while Cronos Group lost over CA$7 million and Tilray lost over CA$18 million. If you back out investment gains, Aphria lost money during the quarter ended August 2018, too.

Furthermore, CannTrust's product mix is arguably one of the industry's best. It generated 52% of its sales from high-margin extracts, rather than lower-margin dried flower, in Q3. By comparison, extracts accounted for 39% of Aphria's revenue in the quarter ended August 2018, and 29% of Cronos Group's sales in Q3 2018. Historically, they've accounted for about 45%of Tilray's sales.

Why CannTrust could skyrocket

In January, CannTrust announced that it filed an application to list shares on the New York Stock Exchange. A listing on a major U.S. market would be important, because it would open up ownership to larger investors. Currently, CannTrust trades on the Toronto Stock Exchange and on the U.S. over-the-counter (OTC) market. However, many institutional investors are prohibited from owning foreign stocks or buying OTC shares because of inadequate volume and less transparent prices.

CannTrust hasn't said when the NYSE might give it an OK, but given that Canopy Growth, Aurora Cannabis, and Aphria have all secured a green light in the past year, I think the odds are that the NYSE approves its application.

A bigger catalyst for the company, however, is the recent approval of an important expansion at its largest greenhouse. The company's already wrapping up an expansion that will increase its production capacity to 50,000 kilograms soon, and this new expansion is expected to increase capacity to 100,000 kilograms by the end of next year.

Last month, CannTrust also revealed that it's on the prowl for additional production capacity "inside and outside Ontario." This suggests that investors could see the company announce later this year a new, larger-capacity target for the future. 

Overall, I think CannTrust's market cap underestimates the potential for its revenue to climb over the next two years because of its existing expansion efforts. If I'm right, then picking up shares now could pay off handsomely.