Following a miserable May that saw nearly three dozen pot stocks lose at least 10% of their value, June was nominally nicer to the green rush. The Horizons Marijuana Life Sciences ETF, an exchange-traded fund holding more than four dozen cannabis stocks of various weightings, rose by a modest 2%.

Then again, the data on individual stocks wasn't as pretty. Of the 60 I follow, just 21 ended the month of June higher (two were unchanged, as well). Pessimism was still readily apparent, but it was the most popular pot stocks -- those generally weighted higher in most marijuana ETFs -- that shone the brightest.

Below you'll find the six best marijuana stocks from June, as well as the likely reason(s) behind their ascent.

A tipped-over bottle filled with dried cannabis, lying atop a pile of paper money

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Innovative Industrial Properties: Up 47%

Cannabis real estate investment trust (REIT) Innovative Industrial Properties (IIPR 1.00%) was the first pot stock to list on a major U.S. exchange. A regular on the top-performers list, IIP was June's best pot stock, with a gain of 47%.

Last month the company acquired its 22nd property, doubling the number of properties it began the year with. Aside from that, the big catalyst was Innovative industrial's mid-month announcement that it was raising its quarterly dividend by 33% to $0.60 per share, for 140% year-over-year growth from its payout in the same quarter last year.

Innovative Industrial Properties benefits every time it adds new assets to its portfolio. Given its average annual return on assets, typically around 15% for many of its deals, observers expect it'll take less than five years for the company to receive a complete payback on its investments.

The only downside to this acquisitive growth is that rental income alone doesn't provide enough capital to make many purchases. Instead, IIP sells its stock to raise money, thereby diluting existing shareholders. Long-term investors should be well aware of those occasional sales of stock to boost capital, and the negative near-term impact they can have on the company's share price.

The arms of two people in business suits, shaking hands

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Tilray: Up 23%

Popular but polarizing pot stock Tilray (TLRY) was the second-best performer in June, with a 23% monthly gain.

The bulk of Tilray's gains came on June 10, when it announced it would be acquiring private equity firm Privateer Holdings in a downstream merger. Privateer currently holds 77% of Tilray's outstanding shares; the concern on Wall Street had been that, even with a voluntary lock-up extension from Privateer on Tilray's stock until the second half of 2019, there would be no orderly way for Privateer to sell down its position without putting serious pressure on Tilray's share price. With Tilray now controlling that sale process over a two-year period, there's no longer any worry about a surprise insider rush for the exit.

Nevertheless, Tilray's solid June doesn't mask its other issues. One is that its strategy shift to focus on Europe and the U.S., instead of Canada, comes at a time when Canada's recreational weed market is just ramping up. While this could wind up being a smart move for Tilray over the longer run, given the larger peak sales potential of Europe and the U.S. relative to Canada, it means pushing any shot of profitability for the company out at least another year. That makes Tilray an easily avoidable marijuana stock, in my view.

A vape pen next to a vial of liquid and neatly arranged dried cannabis flower

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KushCo Holdings: Up 21%

Unlike IIP and Tilray, KushCo Holdings (KSHB) didn't have a well-publicized event that raised its share price by 21% in June. Rather, it seems to be a decision by management that lit a fire under the stock.

My favorite marijuana stock for 2019, and a personal holding, KushCo has been a major disappointment on the earnings front. Although profitability wasn't expected for 2019, KushCo's push for gross margin of at least 30% hasn't come to fruition in recent quarters, with the company absorbing higher import costs for vaporizer products from China. That's a problem given that vaporizers comprise a growing portion of its total sales.

However, KushCo recently announced that it would stop eating those higher import costs, and instead pass along any added costs for vape products to consumers. This is a smart decision because it'll immediately provide a boost to margin, and it should have little (if any) impact on sales. Vaporizers are incredibly popular at the moment, and consumers shouldn't be scared away by modestly higher prices.

A large sign for a marijuana dispensary, with a cannabis leaf and the word Dispensary written underneath it

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MedMen Enterprises: Up 19%

U.S.-based multistate cannabis stock MedMen Enterprises (MMNF.Q), which has been a regular in the "new low" column for much of the year, bucked the trend in June and surged 19%. A combination of expanding dispensary count and a new legalization appear to have fueled the optimism.

Last month, MedMen announced that it was planning to open a 15th store in California, with the bulk of those stores located in Southern California. By 2024, according to the duo of Arcview Market Research and BDS Analytics, California could account for nearly a quarter of the United States' projected $30 billion in licensed-store weed sales. That puts MedMen in good position to succeed if the Golden State's legal marijuana sales really begin to ramp up.

Additionally, Illinois Gov. J.B. Pritzker, a Democrat, made it official by signing a bill that legalizes recreational cannabis. Sales for adult-use weed will begin on Jan. 1, 2020, and MedMen looks like one of the prime beneficiaries. MedMen is in the process of acquiring privately held PharmaCann in an all-stock deal, and PharmaCann already has a presence in the Land of Lincoln.

A close view of flowering cannabis plants growing indoors

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Zenabis Global: Up 16%

Zenabis Global (ZBISF), which is perhaps the most under-the-radar major Canadian pot grower, also reversed a very long downtrend in June by gaining 16%. A production update proved to be the key to Zenabis' end-of-month rally.

On June 24, Zenabis announced that the amount of cannabis it's been harvesting has consistently been outperforming design projections. In May, 672 kilograms of marijuana were expected to be harvested. But the actual harvest totaled 908 kilos, an improvement of 35% over design capacity. With the exception of February, when harvest was 3% below expectations, the other four months (January, March, April, and May) have exceeded design capacity by double-digit percentages. This suggests that Zenabis Global's production forecast might be conservative.

The other boost came from Health Canada approving the company's industrial hemp license, as well as its amendment for phase 2B production at Zenabis Atholville. This amendment boosts capacity from 174,900 square feet to 251,600 square feet, and lifts production at Zenabis' largest grow facility to 22,300 kilos a year from 9,800 kilos.

A cannabis leaf atop a $1 bill, with George Washington peering between the leaves

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Cronos Group: Up 14%

Even the most-hated (by Wall Street) pot stock got in on the action in June, with Cronos Group (CRON -0.45%) rallying 14%. Positive analyst commentary and a surging stock market look responsible for the optimism behind Cronos Group's move higher.

Early in June, Bank of America covering analyst Christopher Carey anointed Cronos with a rare double upgrade, from underperform all the way to buy. Carey also increased Cronos Group's target price to $20 from $13, implying up to 39% upside from the date of his upgrade and note to clients. As reasons behind the upgrade, he cited improved near-term visibility for cannabis derivatives (such as oils, vapes, and edibles) and the company's cash-rich balance sheet.

Cronos Group also likely benefited from the stock market shaking off weakness in May and pushing steadily higher through much of June.

Despite the upgrade, Cronos Group has a lot to prove to Wall Street, and I stand by my initial assessment that it's the most overvalued marijuana stock.