On a tear for much of the year, the S&P 500 Index (SNPINDEX:^GSPC) continued its climb today, adding 13.2 points, or 0.9%, to end at 1,515.6. The advance, however, was not quite enough to keep the index's seven-week winning streak alive, as the S&P ended 0.3% lower for the week.

These three companies didn't help, posting some of the worst declines in the index today:

Tobacco giant Lorillard (UNKNOWN:LO.DL) cratered 3.8%, stumbling after the FDA named a new head of its tobacco unit. The government is considering a move to ban menthol flavoring, which would be a huge hit to the biggest producer of menthol cigarettes in the U.S. That being said, the tobacco industry is constantly dealing with regulation, a fact of life that investors can deal with when dividends sit near the 5.3% rate Lorillard pays out. 

Best Buy (NYSE:BBY) shares dropped 2.2%, just days after investors applauded a move the company made to prevent the devastating practice of "showrooming," which happens when potential customers go to brick-and-mortar stores to interact with products that they end up buying online. Best Buy will expand its price-matching guarantee to online retailers, but investors will have to see if the slimmer margins are able to sustain the business. The retailer is set to report earnings next Thursday. 

The third laggard of the day, First Solar (NASDAQ:FSLR), fell 1.7% a few days before its quarterly report is due Tuesday. The pessimism today was partly caused by a downgrade, citing a "depleting pipeline" in the nascent solar industry. Still, Wall Street expects earnings to climb nearly 40% from the same quarter last year -- a growth rate that's not to be scoffed at.