Truth be told, you practically could have thrown a dart at any decently sized marijuana stock ($200 million market cap and above) and handily have outperformed the broader market. There are quite a few marijuana stocks that have doubled or tripled in value over the past year, and they could potentially move even higher.

The impetus behind this move is twofold for pot stocks. First, we have the tangible improvement in legal cannabis sales that's primarily been sparked by state-level expansion in the United States. Legal weed sales in North America grew by 34% last year according to cannabis research firm ArcView, and they're on pace to grow by between 23% and 27% annually in the years to come, depending on the source. With a majority of weed sales still being conducted under the table, there's more than ample opportunity for marijuana businesses to lure these customers into the legal market.

Two hands holding cannabis leaves.

Image source: Getty Images.

The other factor at work here is the rapidly changing opinion of the American public. Both national pollster Gallup and CBS News showed in their most recent polls that a record percentage of respondents want to see cannabis legalized nationally -- 60% for Gallup, 61% for CBS News. The more favorable this view, the more promise for the marijuana industry.

The result? Marijuana stocks are on fire.

The most undervalued marijuana stocks (but there's a catch)

Unfortunately, it also means that marijuana stock valuations are off the charts for the time being. Nearly all pot stocks are losing money, and those that are generating revenue are valued at exceptionally high multiples to their sales. There really aren't any true "undervalued" marijuana stocks at the moment, and any investment in the space should be seen as high-risk.

But there's a twist to the common convention of valuing marijuana stocks. There are three companies that, if they hit on a few of their near-term goals, could rightly be undervalued based on their current market caps. If things go their way, they could be both fundamentally attractive and truly undervalued in a relatively short period of time.

In no particular order, here are those three companies.

A doctor holding a bag of cannabis buds in one hand and cannabis-infused pills in the other.

Image source: Getty Images.

1. Insys Therapeutics

One marijuana stock that could be valued at less than 15 times its full-year earnings per share (EPS) and under three times sales -- based on its current market cap of $780 million -- in two years' time is Insys Therapeutics (NASDAQ:INSY).

Insys isn't your typical marijuana stock. It doesn't devote its entire drug-development pipeline to discovering cannabinoid-based drugs. For years, its foundation has been built on a sublingual breakthrough cancer pain drug known as Subsys, which more or less accounts for all of its revenue at the moment.

Insys' most recent issues stem from allegations and lawsuits that a majority of Subsys prescriptions were being written for off-label use. As a result, Insys has seen sales of its core product halved from more than $300 million on a trailing 12-month basis in 2015 to a Street expectation of $163 million in sales in 2017. Insys is also projected to lose money in 2017, per Wall Street's consensus.

What could change all this is the impending launch of Syndros in the second-half of 2017. Syndros is an oral dronabinol solution, which is essentially a pharmaceutical version of tetrahydrocannabinol (THC), the psychoactive component of cannabis. It was approved by the Food and Drug Administration (FDA) last year as a treatment for chemotherapy-induced nausea and vomiting (CINV) and anorexia associated with AIDS, but it took months for the Drug Enforcement Agency to schedule the drug. With a schedule II status now reached, Insys is preparing for its launch.

According to Wall Street's estimates, Syndros has the potential to hit $300 million to $400 million in peak annual sales, which is around what Subsys was generating at its peak. The big question mark is whether Syndros is going to be able to successfully navigate a very crowded CINV market. If it can, and Subsys' sales stabilize, Insys could see its sales more than double over the next three years, with annual EPS approaching $1 by 2020. This would make Insys quite an undervalued marijuana stock.

Cannabis buds falling out of a bottle and onto a pile of cash.

Image source: Getty Images.

2. Aphria

Another currently pricey marijuana stock that could very easily become undervalued in the next two years is Aphria (NASDAQOTH: APHQF), a licensed producer and retailer of medical marijuana products in Canada. As a reminder, Canada legalized medical cannabis all the way back in 2001.

Right now, unlike most marijuana stocks, Aphria is actually profitable, which puts it near or at the head of the pack among pot stocks. According to the company's third-quarter earnings results, it nearly doubled its sales to $3.75 million, while its earnings before interest, taxes, depreciation, and amortization (EBITDA) grew year over year by 137%, to about $730,000. Nonetheless, Aphria is probably valued at north of 60 to 70 times its projected 2017 profits, which isn't cheap.

What could change is the expected completion of Aphria's phase IV organic expansion. This fully funded $100 million project is expected to grow Aphria's growing capacity from 300,000 square feet to 1 million square feet, which works out to a capacity increase of 75,000 kgs of cannabis annually. Construction of Part IV is expected to take about a year, meaning by early 2018, Aphria should see a notable bump up in production.

Now, here's where things get interesting. Canadian Prime Minister Justin Trudeau is pushing aggressively to get recreational pot legalized across the country. If the Canadian government votes for the recently introduced legislation, Canadians could legally buy adult-use weed sometime next year. In other words, right as Aphria's major production upgrade comes online, it could see a surge in demand from recreational customers.

There aren't any current EPS estimates available on Aphria, but I could foresee the company earning around $0.30 per share for fiscal 2019 (assuming Canadian approval), placing it at a P/E of about 15, based on its current price. This would make Aphria a potentially undervalued gem.

A lab researcher taking notes in the middle of a marijuana grow farm.

Image source: Getty Images.

3. Corbus Pharmaceuticals

A final marijuana stock that could find itself as being undervalued if things go its way is Corbus Pharmaceuticals (NASDAQ:CRBP). However, unlike Insys, which has two FDA-approved products, and Aphria which is already profitable, Corbus is a clinical-stage drug developer and is, thusly, the highest-risk candidate of these three pot stocks.

Corbus' risk is also derived from the fact that its entire pipeline revolves around one experimental drug, anabasum. Anabasum is a synthetic oral endocannabinoid-mimetic drug that's currently being tested in four separate indications. Despite positive results in a midstage systemic sclerosis study, almost all of Corbus' current valuation rests with the success or failure of its cystic fibrosis (CF) study.

In March, Corbus Pharmaceuticals reported "positive" results from its phase 2 study in CF. The company noted a 75% reduction in annual pulmonary exacerbations compared to the placebo at the highest dosage (20 mg), as well as comparable safety and tolerability with the placebo.

However, Wall Street wasn't too thrilled with the fact that anabasum didn't improve forced expiratory volume within the first second for CF patients, which is sort of a baseline improvement often seen in successful CF medicines. This has some pundits questioning the underlying efficacy of Corbus' lead drug.

The next steps for Corbus include further evaluation of the data to determine the next clinical steps, as well as meeting with the FDA to design a phase 3 study. Assuming Corbus can meet its phase 3 primary endpoint, anabasum could be a huge winner. Though other FDA-approved CF drugs are already on pharmacy shelves, they often target specific mutations of the disease. Since anabasum targets the CB2 receptor of the cannabinoid receptor system found in our bodies, it would be used as a general anti-inflammatory and could, therefore, treat all variations of CF.

If approved, we could be talking about a $1 billion a year drug in peak sales, but that's a big if. Considering that most biotech stocks are usually valued at multiple times their peak sales, Corbus' current market cap of $361 million could prove to be way undervalued, but that's going to depend on its late-stage clinical results.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.