Wednesday has been a turbulent day for the Dow Jones Industrials (DJINDICES:^DJI), which traded up more than 108 points as of 12:30 p.m. EDT. After stocks gave up early gains when Federal Reserve Chairwoman Janet Yellen suggested that investors needed to rein in their dependence on low interest rates, news about an hour ago that Russian President Vladimir Putin had withdrawn troops from the Ukraine border eased tensions in the area and gave investors some hope that the Ukrainian presidential election on May 25 could create a framework for a lasting resolution to the territorial conflict. Still, even with the positive reaction, Merck (NYSE:MRK) remained the worst-performing component of the Dow Jones Industrials, falling 1.5% and adding to its losses from recent sessions. Pfizer (NYSE:PFE)joined its Dow pharma peer on the downside with a 1.2% loss.

Source: Merck.

Merck's decline Wednesday came follows the drug company's deal yesterday to sell its consumer-care business to Bayer for $14.2 billion. The sale includes some of Merck's best-known brand names, including Claritin, Afrin, and Coppertone, giving Bayer access to the worldwide prominence that those brands have developed thanks to Merck's efforts. In the press release yesterday, Merck CEO Ken Frazier established the company's "goal of being the premier research-intensive bio-pharmaceutical company through targeted investments that strengthen our product portfolio and enhance our pipeline," raising some concerns about whether Merck would undertake what could be an expensive shopping spree. Frazier later said investors shouldn't expect a big acquisition along the lines of what Pfizer is trying to accomplish, but shareholders want to see decisive action that nevertheless maintains the value of Merck's ongoing business.

Pfizer's ongoing attempts to acquire U.K. peer AstraZeneca got even more complicated as British Prime Minister David Cameron said he wants to see a greater commitment on the drugmaker's part to make sure it won't dramatically reduce employee counts and investment in the British Isles if a merger were to take place. Cameron's worries on that front should be tempered by the fact that the U.K.'s favorable tax laws that are a key component of the impetus for the merger between the British drug company and the Dow component in the first place. Pfizer has a vested interest in making sure that its presence there is sufficient to satisfy tax authorities on both sides of the Atlantic. Yet with so much uncertainty about the merger right now, shareholders have to feel like the price tag for a successful resolution could rise so high that they won't get any of the benefit of a larger Pfizer.

The Dow Jones Industrials could remain volatile as they get whipsawed by different factors. For the Dow's pharma components, questions remain on how best to pursue growth without overpaying in the process.

Dan Caplinger has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. 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 has a disclosure policy.