Markets responded with disdain today after hiring growth slowed in April to the weakest pace since Sept. 2012. With fresh data also showing clear slumps in manufacturing in the U.S., China, and Australia, all 10 groups in the S&P 500 Index (SNPINDEX:^GSPC) lost ground today. After reaching new all-time highs Tuesday, Wednesday's slip saw the index fall about 0.9%. Below, we examine three of the index's sharpest decliners. 

Shares of JDS Uniphase (NASDAQ:VIAV) lead off today's list, as they cratered 7.3% ahead of what ended up being disappointing earnings. Not only that, but the guidance issued for its next quarter just didn't live up to expectations. That seems to be a theme this earnings season: Even when a company boasts decent results, if future projections aren't up to par, the market will show no mercy. 

Another victim of a weak earnings call, shares of security company ADT (NYSE: ADT) lost 6.9% after posting profits that rose just 2%. Despite adding more than 300,000 new customers, revenue failed to meet expectations, coming in at $821 million -- analysts were calling for about $824 million. While today's slide was extreme, the company isn't exactly in major trouble. It just seems to be in a phase of slow, steady growth. 

Lastly, shares of utilities company ONEOK (NYSE:OKE) shed 6.8% after Morgan Stanley downgraded shares from overweight to equal weight, lowering its price target to $53 per share. The downgrade comes after an earnings report that showed a nearly 6% earnings spike as natural gas became more popular. So even as revenue advanced nearly 4%, the fact that the number was more than 7% below forecasts added downward pressure on the stock.