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 radio equipment maker CPI International (Nasdaq: CPII) are surging today, rising 34% above Wednesday's closing price.

So what: The defense contractor agreed to a buyout offer at $19.50 per share, so the stock jump simply reflects the price premium. A buyout bid from Comtech Telecommunications (Nasdaq: CMTL) fell apart earlier this year because the partly stock-based offer was damaged by a swooning Comtech stock, but this private-equity deal should be set in stone.

Now what: CPI International's share price has now doubled in the past 12 months and more than tripled since the spring of 2009. Despite these gains and the tremendous overnight pop, at least two lawsuits say the company isn't getting full value out of the sale. Don't hold your breath waiting for a bidding war, but do keep in mind that rival L-3 Communications Holdings (NYSE: LLL) actually commands a slightly higher PEG ratio than CPI International, so this boosted price is not crazy-high by any means.

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