Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

Stocks eased downward Tuesday, but not by very much, as investors were content to wait until tomorrow's key announcement from the Federal Reserve about a possible reduction in bond-buying activity. Yet even as some investors are bracing for what they see as an imminent pullback in economic stimulus, Thompson Creek Metals (TCPTF), Spectrum Pharmaceuticals (SPPI), and FactSet Research Systems (FDS 0.60%) all posted dramatic losses on company-specific happenings today.

Thompson Creek Metals fell almost 10% as the molybdenum miner continues to suffer from weak commodities prices. Hopes that the company's Mt. Milligan gold and copper mine could help Thompson Creek find new life got a serious blow earlier in 2013 when gold prices plunged, and with a substantial commitment to streaming company Royal Gold (RGLD 0.17%), Thompson Creek won't even benefit from all of the mine's gold production even once it ramps up to full production in the first half of next year. That doesn't mean that things can't go well for the company if the mine turns out well and if prices start to recover. But with one analyst calling for further losses of almost 75% for the stock, Thompson Creek needs good news to prove bearish investors wrong.

Spectrum Pharmaceuticals dropped 9% after announcing yesterday afternoon that it would make a $100 million offering of convertible notes to raise capital. As we've seen with several offerings lately, Spectrum plans to use hedging strategies to try to reduce any potential dilution from the eventual conversion of the bonds into stock. Nevertheless, shareholders reacted negatively as they often do to offerings with an equity component, and a heavy short-selling contingent might have made the move even more dramatic than it would otherwise have been.

FactSet Research Systems declined 6% as the financial-research provider disappointed investors with poor results guidance in its quarterly report. FactSet's earnings per share landed a penny short of what investors had hoped to see, with revenue also coming in below expectations. The company also cited the potential loss of a tax credit on research and development as prompting a roughly 2.5% reduction in its earnings-per-share projections for its fiscal second quarter, and even a $300 million expansion in its share buyback program wasn't enough to lift shares.