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: Pharmaceutical maker Akorn's (Nasdaq: AKRX) shares are up 12% today on high volume.

So what: The company didn't release any news, but the stock spiked about 40 minutes into the trading day today after a big buy order. More than 2 million shares have traded hands, far exceeding the normal 580,000.

Now what: Buying on a trading spike like this can be dangerous for long-term investors. A big buyer came into the market trading a lot of shares early in the day; support may not last long if that buyer leaves the market. This move just seems a little fishy to me. I'm going to sit this rally out and wait for some real news.

Interested in more info on Akorn? Add it to your watchlist.

Fool contributor Travis Hoium does not have a position in any company mentioned. You can follow Travis on Twitter at @FlushDrawFool, check out his personal stock holdings or follow his CAPS picks at TMFFlushDraw.

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