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 Sunoco (NYSE: SUN) are trading 12% lower than at yesterday's close, after the company completed a spin-off to shareholders today.

So what: The stock's price may have been a surprise if you didn't see the spin-off coming, but don't fear: Your portfolio is actually up on the day. Sunoco gave shareholders 0.53046456 shares of SunCoke (NYSE: SXC) for each Sunoco share they owned.

Now what: The move has been pretty much a wash so far, with Sunoco trading higher later in the day and SunCoke trading lower. Now is the time to consider whether you want to keep one or both of these shares now that Sunoco has fully spun off its stake in the company. Other than that, I see no reason to get too excited about today's move.

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