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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