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.

The stock market suffered another up-and-down day, again finishing on the losing end as investors saw their fear levels rise dramatically after the Fed's latest minutes were released. With less clarity than ever about the Fed's eventual plans to end its quantitative easing program, investors are justifiably concerned. But big losses for Seaspan (ATCO), voxeljet (VJET -40.89%), and Direxion Daily Gold Miners Bull 3x (NUGT 0.99%) showed how vulnerable some investments are to the uncertainty. Let's look more closely at what happened to push these share prices down.

Seaspan fell 10% as the shipping company announced a secondary offering of 3.5 million shares, raising $77 million. The company said it would use the proceeds for purposes that could include acquiring vessels. After a long period of terrible conditions in the shipping industry, Seaspan has started to rebound recently as investors get more optimistic, but it's still too early to tell whether better conditions will last.

For voxeljet, a 32% plunge was the latest in a long series of big moves in both directions since the 3-D printing company came public just last month. Some traders attributed the big move to a report from Citron Research, which included its "realistic price target" for voxeljet of just above $12 per share. With Citron having been involved in several other high-profile short-selling campaigns, momentum investors apparently took the report seriously, although the stock remains above its first-day closing price even after losing more than 40% from its peak levels just two days ago.

Direxion Daily Gold Miners Bull 3x fell 10%, as the Fed minutes prompted a $30-per-ounce drop in the price of gold. For mining stocks, gold's poor performance earlier this year was already enough to create problems, with even major producers Barrick Gold (GOLD 1.68%) and Goldcorp (GG) suspending operations or exploration efforts at key properties due to poor market conditions. Precious-metals investors have worried that higher interest rates resulting from the Fed's easing back from its bond purchases could draw investors away from gold, and the leveraged Direxion ETF's performance only magnifies the impact of gold's drop had today.