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

What: Shares of Mellanox Technologies (NASDAQ:MLNX) climbed 4% today after Craig-Hallum upgraded the semiconductor company from hold to buy.

So what: Along with the upgrade, analyst Rajesh Ghai slightly raised his price target on the stock to $54 (from $52), representing about 35% worth of upside to yesterday's close. Mellanox has been crushed over the past year on a string of quarterly revenue declines, but Ghai thinks the stock is finally due for a short-term bounce.

Now what: While Craig-Hallum isn't exactly bullish on Mellanox's long-term prospects, the risk/reward for the rest of 2013 seems favorable. "Our new $54 price target reflects an ex-cash 20x multiple on our new FY14 EPS estimate of $2.25," wrote Ghai. "We expect MLNX management to place these drivers under the spotlight at the company's upcoming October 25th Analyst Day, which follows its October 23rd earnings report and we recommend investors buy MLNX shares ahead of the event." Of course, given how difficult it is to consistently dance in and out of stocks at a profit, average investors would do well to keep their distance.

Fool contributor Brian Pacampara has no position in any stocks mentioned. The Motley Fool recommends Amazon.com, Apple, Facebook, and Google. The Motley Fool owns shares of Amazon.com, Apple, Facebook, and Google. 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.