It was a pretty ho-hum day on the markets today without significant economic or earnings news to drive stocks. The Dow Jones Industrial Average (DJINDICES:^DJI) fell just 0.13% off its record close on Friday and the S&P 500 (SNPINDEX:^GSPC) closed down 0.09% today. The markets didn't make significant moves but a few stocks did make big moves lower.

Merck (NYSE:MRK) was the biggest loser on the Dow, falling 1.7%. The FDA released some safety concerns about an experimental insomnia drug including daytime drowsiness, suicidal thinking, and problems driving. The drug will go to a panel of experts on Wednesday and there's likely enough evidence to throw out higher doses so the question comes down to lower dosage levels. If the panel doesn't see enough evidence to approve a lower dose, we could be in for another round of testing or the drug could be nixed altogether.  

Cisco Systems (NASDAQ:CSCO) stock was down big in afternoon trading but ended down only 1.2% after a wild run-up last week. The stock was up 14.9% last week so a small pullback today is nothing to be worried about. The only related news was an analyst downgrade of Cisco's FlexPod partner NetApp and a report that Cisco was unlikely to buy the company. After last week's gain, Cisco is up 21.9% for the year and revenue only grew 5.4% in the first quarter so the stock is likely getting ahead of itself, which can cause a sell-off for profit taking, if nothing else.

Verizon Communications (NYSE:VZ) dropped 1.1% on a lot of chatter over a potential Verizon Wireless buyout. Management, media, and analysts have been discussing a buyout of the 45% of Verizon Wireless that Vodafone owns but with a $3.15 billion dividend heading to Vodafone in the near future and nearly $10 billion in annual dividends going forward, it's hard to see why Vodafone would sell for anything but a ridiculously high price to Verizon. Barron's was the latest to point out the challenges with a buyout today and shares are sinking as hope of a buyout fades away.