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 specialty materials producer Ameron International (NYSE: AMN) skyrocketed today, gaining as much as 28% in intraday trading on heavier-than-average volume.

So what: There's no mystery behind Ameron's gain today. Oilfield equipment maker National Oilwell Varco (NYSE: NOV) announced that it's planning to gobble up Ameron for $85 per share. Assuming Ameron shareholders approve the deal, the companies think it could close as soon as the fourth quarter.

Now what: There doesn't seem to be much to do here from the perspective of Ameron's stock. As of this writing, the stock was trading within 1% of the proposed buyout price, so upside arbitrage opportunities are limited. As for betting on the deal falling apart, National Oilwell had slightly more than $3 billion in cash at the end of March, so financing the purchase doesn't look to be a big issue. And while some Ameron investors may have had even higher hopes for the stock, the buyout premium seems pretty generous.

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Fool contributor Matt Koppenheffer does not have a financial interest in any of the companies mentioned. You can check out what Matt is keeping an eye on by visiting his CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool or Facebook. The Fool’s disclosure policy prefers dividends over a sharp stick in the eye.