When the curtain closes on 2018 in roughly eight weeks, it's likely to go down as the most monumental year on record for the legal cannabis industry. Though there have been major advances before -- including California becoming the first state to legalize medical marijuana in 1996 and Uruguay becoming the first country in the world to legalize recreational marijuana -- arguably nothing beats Canada's decision to legalize recreational marijuana in 2018.

When the industry is fully ramped up -- mind you, this will take a few years -- it's expected to generate upwards of $5 billion in added annual sales. This comes atop what growers were already bringing in via medical weed sales and exports to foreign countries. This long-awaited legalization is what's been responsible for sending pot stocks through the roof for years.

A tipped over bottle filled with dried cannabis lying atop a messy pile of cash.

Image source: Getty Images.

The top-five marijuana stocks since the beginning of 2016

Since the beginning of 2016, nearly all marijuana stocks are substantially higher, with some even sporting four-digit percentage gains through this past weekend. The following five marijuana stocks, listed in ascending order, are hands-down the industry's top performers in that time span.

But before we jump right in, please note that because some of these companies have uplisted to more reputable exchanges, prior over-the-counter-listed historical data may not be available. In such instances, share-price change data on the Canadian exchanges may be used, and will be noted below.

A thrilled stock investor pumping his fist while looking at rising charts on his computer screens.

Image source: Getty Images.

5. Aurora Cannabis: Up 1,571%

Although it's a company I might rail on for its acquisition binges and subsequent ballooning of its outstanding share count, grower Aurora Cannabis (NYSE:ACB) has done well for itself and shareholders with a 1,571% gain since 2016 began.

Aurora Cannabis, which recently uplisted to the New York Stock Exchange (NYSE), looks to have the inside track to the peak production crown. Already on pace for more than 570,000 kilograms of annual production, the company's acquisition of ICC Labs in South America will bring 92,000 square feet of existing production and 1.1 million square feet of developing production under its wing. In short, 600,000-plus kilograms seems very reasonable when operating on all cylinders.

With production figures this large, investors seem confident that Aurora will be able to take advantage of economies of scale, thereby producing cannabis at a very low cost. They likely also believe Aurora has what it takes to forge partnerships and land lucrative long-term supply deals given its top-tier production.

There are still a lot of questions left to be answered with Aurora, but there's little denying that it's showed up for shareholders so far.

A person holding a cannabis leaf in the middle of a cannabis grow farm.

Image source: Getty Images.

4. Canopy Growth Corp.: Up 2,602% (on the Canadian exchange)

Speaking of showing up for investors, Canopy Growth Corp. (NYSE:CGC) has kicked butt and taken names since the beginning of 2016. The first Canadian marijuana stock to list on the NYSE has seen its shares rise by a brisk 2,602% in roughly 34 months, according to its Canadian-listed shares.

Canopy Growth is probably going to slide in behind Aurora Cannabis as the nation's second-largest producer. It has 5.6 million square feet of capacity -- 2.7 million of which is already licensed for cultivation by Health Canada -- which should give it roughly 500,000 kilograms of annual yield when fully ramped up. 

What allows Canopy to really stand out are its sales channels, brands, and partnerships, which are light-years ahead of Aurora Cannabis. Canopy Growth's Tweed brand is arguably the most recognizable throughout Canada, and Constellation Brands$4 billion investment in Canopy Growth Corp. gives it a 37% stake in the company. More than just a partnership, the maker of Modelo and Corona beer has a vested interest in Canopy's long-term success. All told, it's not surprising to see this company performing as well as it is. 

A cheering young businesswomen in front of a rising wooden chart line.

Image source: Getty Images.

3. MariMed: Up 3,093%

Perhaps one of the more surprising names you'll find on this list is Massachusetts-based cannabis consulting and grow-facility operator MariMed (NASDAQOTH:MRMD). It's come a long way from its $0.15 share price at the end of 2015, and now sits nearly 3,100% higher.

Unlike Aurora Cannabis and Canopy Growth, which both trade on the iconic NYSE, MariMed shares are listed on the over-the-counter (OTC) exchange. Though the OTC exchange has made strides to improve reporting standards in recent years, volume and institutional interest still tend to be considerably lower. This lack of volume has made MariMed exceptionally volatile over the years and, in recent months, may be at least partially responsible for its surging share price.

Tangibly speaking, investors should be pleased with MariMed's recent acquisitions and investments. Last month, it closed on its acquisition of BSC Group in New Jersey, potentially setting itself up for licensing and consulting market share if New Jersey legalizes recreational pot. MariMed also announced an investment in customer relationship management and marketing software company Sprout.

Again, this is a very thinly traded, money-losing pot stock. But for the time being, being under the radar is probably what's pushing its market value higher. 

An indoor commercial cannabis grow facility.

Image source: Getty Images.

2. Cronos Group: Up 3,313% (on the Canadian exchange)

Among the big boys, no marijuana stock has performed better than Cronos Group (NASDAQ:CRON), which, according to its Canadian-listed shares, are up better than 3,300% since the beginning of 2016.

Cronos Group has likely found support from investors, given that it's on track to be a top-10 producer, once running on all cylinders. In July, the company announced a joint venture with a number of investors to create Cronos GrowCo. When fully up and running, this joint venture will span 850,000 square feet and yield about 70,000 kilograms a year. Combined with its existing grow facilities and brands, Cronos should be capable of approximately 140,000 kilograms of peak annual output. 

Cronos Group also turned heads in early September when it announced a partnership with privately held Gingko Bioworks. The duo will work to extract cannabinoids from the cannabis plant and produce these cannabinoids on a commercial scale. In other words, Cronos Group is moving beyond just dried flower, which is a high-margin (and smart) move. 

Given Cronos' late start to its joint venture greenhouse expansion, it's possible the company could miss out on some lucrative long-term supply deals. Then again, shareholders over the past 34 months aren't complaining.

A tipped over bottle of cannabis buds lying atop a doctor's prescription pad.

Image source: Getty Images.

1. Namaste Technologies: Up 6,750%

However, more than doubling up the second-best performer since the beginning of 2016 is small-cap Namaste Technologies (NASDAQOTH:NXTTF). Having finished 2015 at just $0.02 per share, Namaste has since gained a brisk 6,750% as its telemedicine app and vaporizer business has grown in size.

Without question, the most exciting aspect of Namaste Technologies is its online portal NamasteMD, which was launched earlier this year. Since its launch, NamasteMD has already attracted more than 17,000 patients. Most important, these patients can be kept within the Namaste universe thanks to its wholly owned grow farm CannMart. Being able to lean on its high-margin telemedicine app and internalize its growing costs may result in above-average margins and certainly a unique business model.

Investors are likely also pleased with Namaste's international presence. Its e-commerce platform has over 30 websites in more than 20 countries, diversifying its revenue stream. For example, it saw 364% sales growth in Canada during the fourth quarter, but also 261% sales growth in Germany and 188% in Brazil. 

Although recurring profits are still elusive, and may remain so for some time as Namaste builds out its core infrastructure, long-term investors are sitting pretty.

Sean Williams has no position in any of the stocks mentioned. The Motley Fool recommends Constellation Brands and Namaste Technologies. The Motley Fool has a disclosure policy.