While Fools should generally take the opinion of Wall Street with a grain of salt, it's not a bad idea to take a closer look at particularly stock-shaking upgrades and downgrades -- just in case their reasoning behind the call makes sense.

What: Shares of Intrepid Potash (NYSE:IPI) gained 3% today after Piper Jaffray initiated coverage on the potash producer with an overweight rating.

So what: Along with the bullish call, analyst Brett Wong planted a price target of $21 on the stock, representing about 24% worth of upside to yesterday's close. So while conservative investors might be turned off by Intrepid's price volatility over the past year, Wong's call could reflect a sense on Wall Street that its cash flow prospects are becoming too cheap to pass up.

Now what: According to Piper, Intrepid's risk/reward trade-off is rather attractive at this point. "IPI is a pure play potash nutrient producer, which we believe results in investor apprehension around the stock due to the soft global market conditions for the nutrient category, where global potash prices are at 5 year lows and there does not seem to be relief in sight," said Wong. "Our positive stance on Intrepid Potash is not predicated on an improvement in global potash prices but rather the benefit of Intrepid's geographic location, supplying the relatively stable U.S. market, and the various capital projects nearing completion this year, which improves Intrepid's cash generation and free cash flow profile, potentially opening the door to return capital to shareholders in the near future." Of course, when you couple Intrepid's still-hefty debt load and exposure to volatile potash prices with its red-hot stock of late, I'd hold out for a wider margin of safety before buying too heavily into that bull talk.