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 semiconductor testing specialist Verigy (Nasdaq: VRGY) are soaring 37% above last night's closing price today, while competitor LTX-Credence (Nasdaq: LTXC) has fallen more than 16%.

So what: The two companies have been slated to merge since Nov. 17, but much larger competitor Advantest (NYSE: ATE) has thrown a spanner in the works with a competing bid for Verigy. Whether through merger or buyout, Verigy is surely going somewhere, while LTX-Credence may end up without a partner.

Now what: Verigy's share price now hovers slightly below Advantest's bid price, as if it were a done deal already. LTX-Credence is smaller than Verigy and doesn't have much to offer in a bidding war, but the company is appealing to Verigy's shareholders to go with the lower bid anyhow. A quick closing and lack of regulatory obstacles could still secure the deal for LTC-Credence, but it's one heckuva Hail Mary pass.

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