I was half-right when it comes to Cronos Group (NASDAQ:CRON) stock. In the wake of the investment by Altria (NYSE:MO) last month, I thought CRON stock was a buy. But I also thought the gains in Cronos stock would take some time to play out.

Indeed, as I wrote in December, I was surprised by the lack of enthusiasm toward the Altria investment. Canopy Growth (NYSE:CGC) had soared for weeks after making a similar deal with Constellation Brands (NYSE:STZ,STZ.B). And as I had predicted, Cronos’ deal seemed just as attractive.

Yet CRON stock faded after an initial jump; within just a few sessions, Cronos Group stock traded below where it had before the Altria deal. A market clearly focused on risk wanted nothing to do with CRON or any pot stock. I thought that reticence would hold for some time.

I was dead wrong. In the New Year, investor attitudes have changed quickly – and admittedly much more quickly than I imagined. CRON is up 78% already in 2019. And at this point, it might be time to take at least some money off the table.

CRON Stock and CGC Stock Soar

The case for both Cronos stock and Canopy Growth stock is that the multi-billion investments give both companies a significant leg up.

The cash infusion allows the companies to spend up on R&D and building out supply chains and retail networks. Both Cronos and Canopy Growth can be active in M&A. Neither management team has to worry about raising capital or controlling expenses; rather, the focus can be solely on growth.

For most of last year, as pot stocks soared, investors didn’t 100% buy that argument. Tilray (NASDAQ:TLRY) was one of the biggest gainers in the space. Aurora Cannabis (NYSE:ACB) more than tripled between mid-August and mid-October. Both CGC and CRON gained nicely, but the trading seemed choppy, particularly as broad markets turned south in the fourth quarter.

What we’ve seen in 2019 is a clear pivot to the companies with amassed war chests. As noted, CRON has risen 78% YTD. Canopy Growth stock has risen 89%. The gains elsewhere are more muted, however: ACB up 43%, TLRY up 16%, Aphria (NYSE:APHA) +30%.

So there are two factors at play here. One, investors are buying pot stocks again, amid a more optimistic market. Secondly, those investors are gravitating toward CRON and CGC. But it’s worth remembering that both those tailwinds can fade and likely will at some point in 2019.

The Risks to Cronos Stock

It’s close to impossible to value CRON stock on any real fundamental basis. This is a company valued at over $3 billion that generated $3.8 million in Q3 revenue. That revenue is growing quickly of course, up 186% in the third quarter, and will continue to grow quickly in the future.

How quickly that revenue grows will determine the long-term trajectory of CRON stock. But in the meantime, CRON is going to be a trading vehicle. And with the stock again going parabolic, that suggests some reason for caution at the moment.

Investors are more optimistic toward the market more broadly, and that risk-on trade likely has helped pot stocks. Moves toward hemp legalization are providing a boost. And it appears all will be status quo at the federal level.

But we’ve seen pot stocks  including CRON pull back in a “sell the news” event. And valuations are stratospheric. CRON has had a nice run in what looks like a delayed reaction to the Altria deal. But expecting that run to continue forever is foolish to the point of delusion.

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