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 zinc producer Horsehead Holding (Nasdaq: ZINC) dropped as much as 12.6% overnight on about twice the average trading volume, reminding shareholders of Marlon Brando discussing offers you can't refuse.

So what: The big news on Horsehead today is a fresh debt offering. The company aims to raise between $80 million and $100 million in convertible (read: dilutive) notes to finance the construction of a new zinc-mining facility. Investors seem to be focusing more on the dilutive effects of the offering than on the potential business growth therein.

Now what: This is not the first time Horsehead shares moved in the opposite direction of what looks like good news. The crash makes some sense; one of this five-star CAPS stock's main attractions was its squeaky-clean balance sheet, which won't be the case anymore. Still, this longtime Motley Fool Hidden Gems recommendation has treated investors very well over the last year, with a 47% gain even after this recent drop, beating peer US Ecology (Nasdaq: ECOL) and running close to much larger rival Teck Resources (NYSE: TCK). I see an opportunity here as Horsehead aims to capitalize on a hot market for commodity metals. Now the shares are on sale, too.

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

Fool contributor Anders Bylund holds no position in any of the companies discussed here. Motley Fool newsletter services have recommended buying shares of Horsehead Holding. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool is investors writing for investors.