All three major indexes finished higher on Thursday, as strong numbers from the U.S. manufacturing sector gave the stock market a boost. With worries about the Russia-Ukraine conflict waning but still in the air, markets have advanced this week on cautious investor optimism. But investor optimism was nowhere to be found for Jabil Circuit, (NYSE:JBL), Occidental Petroleum (NYSE:OXY), and International Game Technology (NYSE:IGT) today; each finished as one of the worst-performing stocks in the entire S&P 500 Index (SNPINDEX:^GSPC). The S&P itself finished 11 points, or 0.6%, higher, at 1,872.

Jabil Circuit shares shed 2.9% as Wall Street recoiled at the negative impact that cutting ties with BlackBerry is having on its business. Now, to be fair, BlackBerry made up about 12% of Jabil Circuit's sales before Jabil decided to "disengage" from the beleaguered phone maker. Shareholders have known for some time that BlackBerry's death spiral would also be painful for its suppliers, and that knowledge was built into the stock price. That said, the company's revenue miss yesterday highlights just how difficult it will be for Jabil to replace that business.

Occidental Petroleum fell for a second straight day Thursday as investors continued to react to the city of Carson, California's brand spankin' new drilling ban. Shares lost 2.3% today as fallout from the decision continued. Occidental plans to spin off its California business -- in part because of the difficult regulatory environment in the state -- and the city of Carson imposed a moratorium on new drilling, and suspended talks with Occidental about plans for 200 additional wells until the spinoff is complete. The City Council cited concerns about controversial "fracking" techniques in its decision, apparently not buying Occidental's claim that no such techniques would be used in the wells. 

Finally, International Game Technology fell 2.2% on Thursday. The company makes slot machines and other high-tech gaming products, and has also invested heavily in mobile and social gaming in recent years. Today's slump isn't as bad as it appears; about half of the decline can be chalked up to IGT shares going ex-dividend today. Ex-dividend dates have a downside bias, as some short-term investors sell their shares with the assurance that they'll still receive the next quarterly dividend, anyway. Of more concern to the long-term picture, however, is the future of social gaming, and the company's ability to cash in on the potentially lucrative trend. IGT ponied up $500 million to acquire social gaming company DoubleDown Casino in 2012, only to see its founders leave the company earlier this year as the acquisition's success soured.