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 solar panel specialist Evergreen Solar (Nasdaq: ESLR) tumbled as low as 11% in intraday trading on unusually high volume.

So what: As of yesterday's close, Evergreen Solar had rocketed more than 65% over the past month alone, so today's heavy sell-off shouldn't exactly come as a surprise. Other red-hot October solar stocks LDK Solar (NYSE: LDK), Ascent Solar (Nasdaq: ASTI), Suntech (NYSE: STP), and JA Solar (Nasdaq: JASO) are also down more than 5% today.

Now what: This past Wednesday, I speculated that the solar sector may be in for the proverbial pullback. With oil down only about 150 basis points today, we're seeing just how volatile these solar stocks -- often viewed as leveraged energy bets -- can really be. Of course, with so much bullishness about upcoming solar orders, today's plunge might serve as a nice entry point for long-term investors. Just don't be upset with me if I'm still too scared to jump in.

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