Stocks finished the week on a higher note Friday, as surprisingly strong real estate numbers brought out the bulls today. April housing starts soared, rallying more than 13% from March levels as developers got busy as the cold weather abated. Regardless of how busy developers were getting, investors in Chesapeake Energy Corporation (OTC:CHKA.Q), Cliffs Natural Resources (NYSE:CLF), and NetApp (NASDAQ:NTAP) still headed for the exits. The three stocks ended as the worst performers in the entire S&P 500 Index (SNPINDEX:^SPX) on Friday. The S&P, for its part, added seven points, or 0.4%, to end at 1,877 today.

Shares of Chesapeake Energy shed 4.7% in trading as the company announced a flurry of strategic sales and spinoffs intended to reduce its leverage and shore up its balance sheets. The company should raise more than $4 billion in 2014 from the moves, which will reduce debt by $3 billion. As a result of these divestments, the oil and natural gas company expects to see production hit by 2% this year, while also expecting its growth rate in 2015 to slow markedly.

Cliffs Natural Resources' mining operations. Source: Company website.

Coal and iron ore miner Cliffs Natural Resources lost 3.3% today, as the stock took a hit from an analyst downgrade. Wall Street research firm Macquarie downgraded shares from a neutral to an underperform rating, just days after Cliffs Natural reported its first-quarter results. The company's coal business is hemorrhaging money, extracting coal for an average of $119.41 a ton, only to sell it for $88.61 a ton to its customers. As any kid with a lemonade stand can tell you, this is a broken business model.

Downbeat analysts were also the bane of NetApp's existence today, as the stock tumbled 2.8%. The data storage and solutions company has seen its stock price target lowered at two consecutive Wall Street firms: Wednesday, Piper Jaffray cut its target from $52 to $40 a share; yesterday, Wunderlich trimmed its target price from $44 a share to $34 a share. Each analyst seems to think growth is stagnating at the company, an opinion shared by a Raymond James analyst on Monday, who downgraded the stock on its falling market share.