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 Huntsman (NYSE:HUN) climbed 2% this morning after Goldman Sachs upgraded the specialty chemicals company from neutral to buy.

So what: Along with the upgrade, analyst Robert Koort boosted his price target to $29 (from $22), representing about 29% worth of upside to yesterday's close. While value investors might be turned off by Huntsman's recent share-price surge, Koort believes there's plenty of room for profit and multiple expansion given the company's exposure to the recovering global economy.

Now what: Goldman lowered its 2014 earnings-per-share estimate for Huntsman from $2.12 to $2.02 but raised its 2015 view from $2.24 to $2.41. "With a broad collection and quality of businesses, HUN offers attractive cyclical leverage to a global economic recovery at modest valuation levels, in our view," noted Goldman. "The planned ROC TiO2 transaction (not in our estimates) will further amplify HUN's cyclical exposure pending closure of the transaction in early 2014 as expected by HUN." When you couple Huntsman's hot and volatile stock price with its still-hefty debt load, however, I'd wait for a much wider margin of safety before listening to Goldman on this call.