On the surface, the marijuana industry looks like a once-in-a-generation growth opportunity. It generated $12.2 billion in global sales in 2018, and Wall Street investment firm Cowen Group is calling for $75 billion in global annual sales by 2030. If Cowen's estimate is accurate, we'd be looking at an industry capable of a compound annual growth rate of almost 17% over the next 12 years.

Growing pains kept me away from this budding industry for years

But this is also an industry facing some very apparent teething pains, especially in Canada, which became the first industrialized country in the world to legalize recreational pot, in October 2018.

Today we have dug up three Canadian cannabis stocks that have the lowest price-to-sales ratio [trailing twelve month (TTM)].

Low price-to-sales ratio is indicative of undervaluation. The selected cannabis stocks have a market capitalization in the range of $40 million to $130 million.

Tilray (NASDAQ:TLRY) beat Wall Street's revenue expectations but didn't meet analysts' bottom-line estimates when the company reported its fiscal 2018 fourth-quarter results in March.

But the news was better when Tilray announced its fiscal 2019 first-quarter results after the market closed on Tuesday.

Early supply-chain issues in Canada and California aside, the marijuana industry really has the feel of a once-in-a-generation growth opportunity.

It racked up $12.2 billion in global legal sales in 2018, and Wall Street investment bank Cowen Group is calling for up to $75 billion in worldwide sales by 2030. For you math-phobes, that's a compound annual growth rate of almost 17% over the next 12 years.

The marijuana industry has seen a large amount of incremental shifts over the course of the past few months. In that time, we have not only seen legislation change, but we have also seen the world become more accepting of the miracle substance.

This has led to one of the most inviting investor spaces that we have seen, which has helped to bring market capitalizations even higher. The hopes are high that the industry can continue to flourish as companies move forward with the production of new groundbreaking products.

Today we have identified four Canadian marijuana stocks that have the highest volatility as measured by beta. Beta is a measure of a stock’s volatility in relation to the market. The selected cannabis stocks have a market capitalization in the range of $75 million to $7 billion.

Marijuana stocks are among the most fashionable investments on the TSX. With some stocks in the sector up as much as 70% year to date, they’ve been beating the market with ease. If you’d invested $1,000 in Canopy Growth three years ago, you’d have $23,000 in the bank today — and that’s not the only marijuana stock that has made investors rich. The weed sector as a whole has been beating the market and making many investors happy in the process.

Cannabis stocks had a case of the Mondays and declined steeply in a rough start to the week, with broad drops across North American markets. The North American Marijuana Index, which tracks the top cannabis stocks in the US and Canada, was down 4.2% to 268.6 points by Monday midday. The Horizons Marijuana Life Sciences Index ETF was down 4% at C$19.50.

HEXO Corp (NYSE:HEXO)(TSX:HEXO) is one of the best performing marijuana companies on the stock market in 2019. Its performance—so good, that HEXO stock has already doubled since the beginning of the year. This is the result of revenue reports that reflected year-over-year growth of 1,269%. A sales increase of 144% from the previous quarter, also helped.

With recent volatility in the stock market, many cannabis stocks have performing poorly over the past week.

Today we’ve identified four Canadian cannabis stocks that have performed well over the past seven days, despite the recent volatility.

We also looked at the 7 Day Average Daily Volume of these stocks relative to their 30-Day Average Daily Volume.

A higher 7 Day Average Daily Volume suggests a bullish outlook the stock.