Alberta's latest cannabis growers said Tuesday they remain bullish about the nascent industry despite a major sell-off of pot stocks that has sent share prices tumbling for months.

After submitting its application for a production license four years ago, Airdrie's Sundial Growers secured Health Canada's approval last week, becoming the third legal producer of medical marijuana in Alberta.

The facility west of Airdrie is relatively small for the industry, at 30,000 square feet, but the company plans to break ground in the coming weeks on a $120-million grow-op spanning 400,000 square feet in the central Alberta town of Olds.

Sundial, which remains privately held, has not faced any problems raising money through private equity deals to fund its expansion, despite indications of investor fatigue in public markets, said Stan Swiatek, the company's founder and chief operating officer.

Swiatek said there is a race underway across the cannabis industry to build production facilities big enough to capture a slice of the medical and recreational markets — and investors have been supporting the growth.

"You're forced to be large," he said, adding Sundial has no immediate plans to become publicly traded, but likely will be in the future.

Canadian cannabis stocks have taken a nosedive since hitting a peak in April, shortly before Ottawa tabled its bill to legalize pot, amid an industry-wide sell-off.

There are widespread concerns that cannabis companies are overvalued on the stock market, while analysts also suggest the arrival of several new producers in the past several months has sparked investor fatigue.

Aurora Cannabis, Alberta's first cannabis producer and one of the country's largest marijuana companies, closed at $2.15 each Tuesday afternoon, down by a third from its April peak and almost 10 per cent below the first day of trading in 2017.

Acreage Pharms, which owns a small production facility with potential to expand on 60 hectares of land west of Edmonton, was Alberta's second company to receive a license to grow by Health Canada late March.

A month later, Vancouver-based Invictus MD Strategies Corp. announced it was buying Acreage Pharms for shares and cash worth $42 million, based on its share price at the time.

Invictus, which owns stakes in a licensed grower in Ontario and a fertilizer supplier in B.C., has seen its share price fall by a third since the April peak along with the rest of the industry. Valued at nearly $53 million on the stock market, the company saw its shares close Tuesday at $1.39 each.

Trevor Dixon, the chief executive of Invictus and Acreage Pharms, said investors have been attracted by the company's growth plans and its debt-free balance sheet.

Invictus reported late May it had raised $25 million by issuing shares and would use the cash to fund its expansion plans.

"We have the cash to grow an awful lot," Dixon said.

Once cannabis companies secure licenses to grow medical cannabis, they must undergo additional scrutiny to get Health Canada's approval to sell it, a process that's underway at both Acreage Pharms and Sundial Growers.