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 vinyl products maker Axiall (NYSE:AXLL) dropped 16% today after reporting earnings.

So what: Sales were up 23% to $1.06 billion, driven by the January chlorine asset acquisition from PPG Industries. The problem is that analysts were expecting $1.13 billion in revenue. Even worse, adjusted earnings per share fell to $0.75, which was way below the $1.18 Wall Street expected.  

Now what: Margins were significantly lower than expected, likely because of ethylene prices, which is why the earnings number was so low. Analysts were expecting even higher earnings of $1.50 in the second quarter, so this puts that level of profitability into question. I don't see any strong catalyst higher for Axiall and certainly wouldn't be a buyer after very disappointing quarter.

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Fool contributor Travis Hoium and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.