2018 was a remarkable year for the legal marijuana industry. Indeed, last year may eventually be thought of as the year in which legal cannabis companies emerged in the international financial world. Among other important developments, 2018 brought the nationwide legalization of recreational cannabis use among adults in Canada, as well as the approval by the U.S. Food and Drug Administration of the first cannabis-derived drug treatment. Further, the Farm Bill was signed into law in the U.S., legalizing hemp and certain cannabidiol oils in the process. A flock of new cannabis companies launched, although few began to trade in the U.S. At the same time, investors eagerly anticipated a burgeoning industry.

Nonetheless, in spite of all of the reasons for optimism, many marijuana stocks actually performed quite poorly in 2018. Most pot stocks actually failed to meet performance expectations for the year, which is particularly disappointing compared to relatively strong years in 2016 and 2017. All told, multiple marijuana stocks actually lost more than half of their value across 2018.

Below, we'll take a look at the worst-performing marijuana stocks of 2018 in terms of overall stock performance. We'll compare these companies against the S&P 500 as a benchmark.

1. Namaste Technologies

Performance in 2018: -75.2% vs. -6.2% (S&P 500)

2. Wayland Group

Performance in 2018: -67.6% vs. -6.2% (S&P 500)

3. Insys Therapeutics (INSY)

Performance in 2018: -63.6% vs. -6.2% (S&P 500)

4. Aphria (APHA)

Performance in 2018: -61.3% (APHA) vs. -6.2% (S&P 500)

5. Radient Technologies

Performance in 2018: -60.7% vs. -6.2% (S&P 500)

6. Liberty Health Sciences

Performance in 2018: -58% vs. -6.2% (S&P 500)

Namaste Technologies

Namaste Technologies focuses on medical marijuana, and particularly on the e-commerce potential of this portion of the cannabis industry. Back in 2017, Namaste expanded to add CannMart Inc., a Canadian distribution network, into its portfolio. Currently, the company is working on developing a worldwide cannabis e-commerce platform called NamasteMD. However, Namaste stock tanked following a report from Citron Research in October that accused the company of lying to shareholders and regulators, hiding U.S. assets in an attempt to be listed on U.S. exchanges and selling assets to insiders. Namaste has denied these accusations, but the damage had already been done.

Wayland Group

Wayland Group enjoyed several successes throughout 2018: the company entered into supply agreements with multiple Canadian entities, enjoyed its first high yielding harvest in Germany, and shipped its first CBD capsules to the German market. However, it failed to yield impressive financial figures. For Q3 of 2018, for instance, Wayland's revenue was just over $225,000, only about a third of its revenue for the same period one year prior.

Insys Therapeutics

Insys Therapeutics suffered a series of losses and failures throughout 2018. The drug developer saw its lead drug Subsys suffer sales losses early on in the year. Later, a second drug failed to meet performance expectations as well. Syndros, a drug designed to treat nausea and vomiting associated with AIDS treatment, is based on a synthetic form of THC. Unfortunately, in spite of promising potential, Syndros was only able to generate under $3 million in sales for the first three quarters of the year.

Aphria

Like Namaste, Aphria also suffered devastating losses owing at least in part to negative headlines toward the end of the year. In December, a report emerged alleging that Aphria had overpaid for useless Latin American assets, with implied wrongdoing on the part of Aphria insiders. Similarly to Namaste, Aphria has denied these allegations. However, investors lost trust in the company as a result of the accusations, and the stock price fell heavily as a result.

Radient Technologies

Radient Technologies is a chemical extraction company. So far, however, the company has struggled to provide commercial cannabis extraction services to scale and with a proven record of success. Still, in late November of 2018, the company reported its Q2 results, including revenue of more than $155,000, which marks an increase of about 166% year-over-year. The company also retains a strong balance sheet. It seems that Radient may have simply been caught up in general poor performance across most of the cannabis space last year.

Liberty Health Sciences

Florida-based Liberty Health Sciences is a medical marijuana dispensary. It has close ties with Aphria; Aphria previously owned a significant stake in Liberty, and executive leadership has overlapped between the two businesses.

Unfortunately for Liberty, the scandal which plagued Aphria may have prompted some investor skepticism about Liberty as well. Liberty faced significant losses late in the year. On the other hand, though, Liberty may be poised for success as 2019 develops. The company has one of just a dozen or so cannabis licenses across all of Florida, a state in which the medical marijuana market could rise to $1.7 billion in the next three years. Liberty has continued to expand its reach across Florida by adding multiple new dispensaries. With continued expansion, Liberty could enjoy market share of as much as 25% of the Florida legal cannabis space. At the same time, it has plans in the works to expand outside of Florida as well. All of this could potentially spell success for this company.