What happened

Shares of fertilizer producer Intrepid Potash (IPI 0.05%) stock closed 10% higher on Monday.

So what

I rather doubt that Intrepid Potash itself had much to do with its stock's move, however. Although the company informed investors last week that it will be releasing Q2 earnings soon (on Aug. 2), that fact alone doesn't seem like the kind of thing that could spark a move like the one we saw today.

Rather, the defining event that appears to have catalyzed Intrepid Potash's move was an upgrade for another potash stock -- PotashCorp (POT) to be precise. Just before 10 a.m. this morning, StreetInsider.com reported that analysts at Scotiabank had upgraded shares of PotashCorp to "sector outperform" (i.e., "buy") and assigned the stock a price target of $20 a share -- 23% higher than where shares were trading before the upgrade.

That news sent PotashCorp stock up 5.2% and appears to be the reason Intrepid Potash shares, too, began climbing higher around 10:30 a.m. this morning.

Analyst holding stock arrow up

One analyst likes one potash stock, but which one is it? Image source: Getty Images.

Now what

Should you chase these shares higher? In a word: no.

For one thing, the upgrade that sparked this morning's rally didn't concern Intrepid Potash at all, but PotashCorp instead. For another, there aren't even any publicly available details  on why Scotiabank liked PotashCorp -- and thus no assurance that whatever has the banker enthusiastic about one fertilizer producer is applicable to an entirely different fertilizer producer.

And given the differences between the two stocks -- notably, the fact that PotashCorp is profitable while Intrepid Potash is not -- I'd say that if you feel compelled to buy any potash stock at all now, you're probably better off buying the one that won the upgrade, and not the one that didn't.