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 Hercules Offshore, (UNKNOWN:HERO.DL) slipped about 3% today after Goldman Sachs downgraded the shallow-water driller from neutral to sell.

So what: Along with the downgrade, analyst Waqar Syed lowered his price target to $3.60 (from $4.60), representing about 17% worth of downside to Friday's close. So while contrarian traders might be attracted to Hercules' big drop on Friday, Freedman's call could reflect a sense on Wall Street that its operating challenges are just too difficult to allow for a significant turnaround.

Now what: Goldman cut its 2014 and 2015 EBITDA outlook for Hercules by 25% and 13%, respectively. "After the close on June 19, HERO announced contract cancellation for 2 jack-ups putting at risk ~$300mn of revenues modeled for the next 3 years," noted Syed. "While the stock's 11.7% fall on June 20 somewhat reflects this news, it doesn't fully incorporate weakening near-to-medium term fundamentals. Moreover, revised consensus estimates are still too high, in our view. HERO's GOM based jack-up fleet faces utilization challenges owing to hurricane season, customer consolidation and likely influx of rigs from Mexico." Given Goldman's solid track-record of call-making -- currently ranked in the top 10% of our CAPS community with an accuracy of 75% -- Hercules bulls might want to take a closer look at those risks. 

Brian Pacampara has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.