Despite celebrating the fifth anniversary of the beginning of the bull market, the S&P 500 (^GSPC 1.20%) wasn't in the mood to celebrate, with the index falling 2% over the past week. Continuing worries about what will happen between Ukraine and Russia weighed on the market, which fell on four out of five trading days. The worst performer in the S&P was General Motors (GM 4.37%), but several other stocks dropped almost as much, including Diamond Offshore Drilling (DO), Wynn Resorts (WYNN 1.38%), and priceline.com (BKNG 2.05%).

General Motors dropped more than 9% in the wake of a massive recall of cars that had ignition-switch defects. The problem involves the Chevy Cobalt and five other cars featuring the Chevrolet, Pontiac, and Saturn brands manufactured from 2003 to 2007, with the potential for slipping ignition keys inadvertently turning the engine off. Although the problem isn't hard to fix, the real issue for General Motors at this point is that the automaker knew about the defect as early as 2001, yet the company chose not to take action. Now, class action lawsuits are starting to emerge, and what GM does from here could be critical in whether it continues its impressive rebound since emerging from bankruptcy.

Diamond Offshore fell almost 9% in a tough week for the entire drilling industry. For the past several years, a huge boost in deepwater drilling activity has been supportive for the industry on the whole. But the problem that Diamond faces is that its fleet is much older than those of some of its rivals, with its average age for its floater fleet just under 30 years. Although Diamond has plans to have newbuild drill-ships delivered in coming years, some fear that dayrates for those ships could fall substantially from current levels by the time they're available for Diamond.

Wynn Resorts declined almost 7% despite the company's continuing belief that it can squeeze more from its Macau casinos. Wynn is impatiently awaiting completion of its Cotai Strip project, which it expects to open in early 2016. Yet the larger-scale issue facing the entire gaming industry is that economic tensions in China could lead to a pullback in gaming activity in Macau. Even with the week's decline, Wynn has still almost doubled in the past 12 months, and a small correction could be good for investors seeking to add to positions.

Priceline also posted about a 7% drop. Geopolitical tensions are bad for international travel, and Priceline's strength over its competitors has come from its early mover status in seeing the potential of building a worldwide network of hotels serving key travel destinations. If trouble in Ukraine spreads elsewhere around the world, then the impact on Priceline could be huge, especially given the stock's impressive and almost uninterrupted gains over the past decade.

Stay informed
As the S&P 500 has been under siege from the Ukrainian situation, you need to keep watching the stocks that get hit the hardest. That will leave you better prepared to deal with what could happen next.