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.

Interested in more info on Verigy? Add it to your watchlist.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. 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 is investors writing for investors.