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 coal miner Alpha Natural Resources (NYSE: ANR) are trading up by about 1.3% today, happily chugging along at one-third of average daily trading volume. Except ... some financial info services reported a daily high of $69.60 per share, which is a massive 23.7% spike.

So what: Like I said, only some services show that dramatic jump: Yahoo! Finance, the official NYSE quotes, and Nasdaq services all show Alpha Natural topping out at $57.08 today. Both of my brokerage services agree with Yahoo! and friends, but Google Finance and CNN Money both report that bizarre spike.

Now what: So either some poor soul got a really bad trade through BATS Trading that didn't register on competing services, or else something's amiss with the BATS data feed. Either way, it's a little bizarre -- Google Finance is supposed to get its real-time data directly from the Nasdaq and Yahoo! once signed a real-time data deal with BATS. Maybe things have changed since last time I checked; it's not trivial to find out where each service gets its data from. In any case, this is a reminder to never trade with market orders, just in case you're the next investor caught on the wrong end of a blip like this.

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