Marijuana stocks have been particularly hot of late —  if not before then. And Canadian producer Cronos Group (NASDAQ:CRON) has been a beneficiary. The Cronos stock price is up 14% on Tuesday as I write this; CRON has nearly quadrupled from early December prices.

The gains, however, have been accompanied by some significant volatility. CRON stock plunged last week when short seller Andrew Left of Citron Research — who has targeted Shopify (NYSE:SHOP), Valeant Pharmaceuticals (NYSE:VRX), and many other stocks in his career — took aim. The CRON stock price fell over 28% — yet still was up over a week after huge gains the previous four sessions.

CRON is regaining much of the ground lost after the Citron bear raid — but from here it looks far too expensive. I thought the stock was intriguing last month — but with a potentially stretched valuation at $8. In the double-digits, there are two good reasons why investors should stay patient with Cronos stock — and should believe the stock will come back to Earth at some point.

The Marijuana Bubble?

Having seen the dot-com bubble up close from a trading desk, I’ve retained a healthy skepticism toward stampeding investors. And the marijuana stocks space has gone something close to nuts over the past few weeks, since Constellation Brands (NYSE:STZ)(NYSE:STZ.B) invested $4 billion into Canopy Growth (NYSE:CGC). The Cronos stock price has almost doubled, as has CGC. Tilray (NASDAQ:TLRY) — a pot stock that Citron actually recommended — has nearly tripled, moving from $25 to $72.

The three companies combined now are worth about $17 billion — on the back of roughly $100 million in combined trailing 12-month sales. Obviously, the opportunity is huge — but it’s also an opportunity that will take years to develop. Competition will be intense — as Citron pointed out, there already are over 100 licensed producers in Canada — and pricing pressure will come around at some point.

These types of stampedes often end poorly (with cryptocurrency stocks a recent example) — at least for some participants. The lesson of the dot-com bubble, indeed, is not that investors were wrong about the influence of the Internet on modern life, or the potential for profit. Rather, they were wrong on who would profit — and by how much. And in many cases, forward-looking models seemed to suggest that every competitor in a given space would be dominant — which is not how it worked there, or will work here.

Why Cronos?

So the second reason to be skeptical of Cronos is that even if marijuana stocks aren’t in a bubble, Cronos stock doesn’t seem to be the best play. Its revenue is a fraction of that of Canopy or Tilray. It has no medical presence unlike Tilray, which already has a multi-country export business.

If an investor is going to be on marijuana being a long-term, multinational trend, why not buy the leader? And there’s an interesting parallel (with admittedly some very important difference) to the craft beer initial public offering boom of the mid-1990s. Boston Beer (NYSE:SAM) went public at $15 per share. The stock stayed underwater for a six years — even with a huge first-day pop — before finally taking off. It’s now returned nearly 2,000% on that IPO price.

But Craft Beer Alliance (NASDAQ:BREW), which went public as Redhook in 1995, trades under $19 against an IPO price of $17. Pete’s Brewing, Hart Brewing, Rock Bottom, and many others went bankrupt — or close.

Craft beer turned out to be a massive industry with years of growth ahead of it. Legal marijuana surely will be an even larger industry — but that doesn’t mean the first movers will win. And the trajectory of the craft beer space strongly suggests that investors should focus on the industry leaders — not “me-too” public stocks trying to cash in on a larger trend.

Will the Cronos Stock Price Come Back?

In the near term, it’s likely that little of this will matter. There’s a huge appetite for marijuana stocks — and scores of traders targeting the space. Whether it’s a bubble or simply investors recognizing a multi-billion-dollar opportunity, the gains in CRON stock and its peers can continue for some time.

But that’s not an environment for investors — but speculators. And at some point, the frenzy will die down — and the CRON stock price (and perhaps CGC, TLRY, and other pot stocks) will as well. In the worst-case scenario, Cronos stock looks dramatically overvalued. If that’s not the case, at some point the stock will settle — and long-term-focused investors can act accordingly.

As of this writing, Vince Martin has no positions in any securities mentioned.