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 Globe Specialty Metals (Nasdaq: GSM) fell as much as 12% today after the company was downgraded by an analyst.

So what: Jefferies analysts downgraded the company's shares from buy to hold because it thinks low silicon prices will hurt earnings. Weakness in Europe and the solar market are expecting to keep prices low into the second half of the year, according to Jefferies.

Now what: This type of move from an analyst can be a good buying opportunity for long-term investors. Globe Specialty Metals has been within $0.04 of earnings in the last four quarters and has beaten estimates four times. So, the market is now pricing in a disappointing start to the year, with shares trading at a 52-week low. Next year's earnings estimates are at $1.52, so the stock is trading at a decent value.

Interested in more info on Globe Specialty Metals? Add it to your watchlist by clicking here.