Few if any industries have been as impressive over the past couple of years as the legal cannabis industry. With Canada becoming the first industrialized country in the world to wave the green flag on adult-use pot, and more than 40 countries giving the OK to medical cannabis in some capacity, Wall Street and investors are clearly expecting big things from this industry.

Looking for winning marijuana stocks? Two that probably should be on your short list are Aurora Cannabis (NYSE: ACB) and Scotts Miracle-Gro (NYSE: SMG).

Shares of Aurora have soared more than 80% so far this year, while Scotts Miracle-Gro stock is up more than 35%.

If you can afford to invest in only one marijuana stock right now, though, there are plenty of things to consider when choosing between Aurora and Scotts. Here's what you need to know to decide which of these two marijuana stocks is the better pick.

If you're considering pot stocks for your portfolio, you could be on to something. The marijuana market is worth $150 billion per year worldwide, and the potential to create new cannabis-derived products, including beverages and edibles, has beer and wine giant Constellation Brands (NYSE: STZ) thinking legal marijuana sales could eclipse $200 billion in 15 years.

The hype in the cannabis sector picked up from where the excitement in the most popular cryptocurrency ended. Both the cryptos and cannabis created bandwagon effects. Bitcoin’s glow as an emerging investment opportunity faded. Will the pre-ordained largest cannabis producer suffer the same fate?

Aurora Cannabis Inc. (TSX:ACB)(NYSE:ACB) can be the representative of cannabis in the same breath as Bitcoin is in the cryptocurrency world. That could happen in the event the company’s annual production jumps by 36.84% from 570,000 kilograms to 780,000 kilograms not later than 2022.

Interest in the marijuana industry is heating up among investors, and for good reason. Since the year began, the very first tradable cannabis exchange-traded fund, the Horizons Marijuana Life Sciences ETF, has practically tripled the returns of the broad-based S&P 500, which is having a stellar year of its own.

Speculation continues in the cannabis sector. Investor preference can change in a day or a week as no weed stock has exhibited momentum that could sustain or last longer than seven days. You can’t blame investors for being flaky given the repeated price spikes and dips.

Aphria Inc. (TSX:APHA)(NYSE:APHA) and Hexo Corp. (TSX:HEXO) are not the industry leaders, but are major players in the cannabis space. The pair belongs in the lower rung based on market capitalization ($2 billion to $3 billion bracket). Canopy Growth’s market cap (TSX:WEED)(NYSE:CGC) is 10 times more.

“It’s been a pretty tough, long winter for us. We both have families and we’ve had to make financial sacrifices,” said Breault, whose shop “Green Easy” remains shuttered as they await approval from Alberta Gaming, Liquor and Cannabis, the provincial agency overseeing Alberta’s cannabis industry.

Last week, the AGLC said an improving supply of marijuana allowed them to begin issuing 26 more retail licences, a slight easing on a moratorium bringing the number of Alberta retailers to 101.

But the slight increase in cannabis availability is still not enough to completely lift the moratorium, leaving an estimated 600 prospective pot retailers stuck in limbo.

No. 2. Runner-up. Second fiddle. All these terms have applied to Aurora Cannabis (NYSE:ACB) over the past couple of years. Even as the Canadian marijuana producer made one acquisition after another to fuel growth, it seemed to still always trail behind one other company. That company, of course, is Canopy Growth (NYSE:CGC).

The battle for supremacy in the marijuana industry is intensifying.

While Canopy Growth and Aurora Cannabis have managed to capture about 50% of the Canadian market, other pot companies are attempting to improve their positions. Some firms are successful at doing so, and others, not so much.

Let’s look at two marijuana companies to watch this coming May: Hexo (TSX:HEXO) and Cronos Group (TSX:CRON)(NASDAQ:CRON). One of these firms is currently flying high, and the other recently posted disappointing financial results.

The world needs weed — and for marijuana products manufacturer Tilray (TLRY), that’s both a problem and a source of potential profit.