Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Aeroflex Holdings (NYSE: ARX) have popped by as much as 21% today right after market open before calming down a bit on the heels of an upgrade by Goldman Sachs, who added the company to its "Conviction Buy" list.

So what: Goldman also assigned a price target of $15, which would represent nearly a 64% premium over yesterday's closing price of $9.16. Teradyne's (NYSE: TER) recent acquisition of privately held LitePoint Corp, who provides production-line test equipment for wireless devices, "underscores tremendous value" in Aeroflex, according to Goldman analysts. In addition to providing radio frequency and microwave integrated circuits, Aeroflex also sells test equipment to the wireless and defense industries.

Now what: The $15 price target isn't entirely unreasonable, considering that Aeroflex shares were nearly $19 as recently as early July. The company has gotten punished multiple times in past couple months after lowering its fourth quarter outlook and issuing soft first-quarter guidance after announcing earnings. Combine that with the 13.3% short interest at the end of August, and you have the recipe for a potential short squeeze if given a positive catalyst. Investors may have negatively overreacted to recent events, since top-line revenue grew by 11.3% last year (even if it was a little shy of analysts' expectations). Ultimately, the key to long-term success is the strength of the underlying business, not short-term expectations.

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