The number of housing starts in January fell by 8.5%, way more than economists had been expecting. Additionally, confidence levels among homebuilders also dropped for the first time in almost a year. After that disappointing housing news was released today, all the major indexes began trading lower. As of 12:45 p.m. EST. the Dow Jones Industrial Average (DJINDICES:^DJI) is down 20 points, or 0.15%, to 14,015. The S&P 500 and the NASDAQ are both performing slightly worse, down 0.42% and 0.59%, respectively.

So who's down and why?
For the second day in a row, shares of UnitedHealth (NYSE:UNH) are down 1.7%. The continuous slide owes to the profit warning Humana released yesterday. Due to the government's proposed 2014 Medicare Advantage rates, which Humana claims are too low, the company is projecting that its profit will take a hit next year. The proposed rate change will affect not only Humana but the whole health insurance industry, which includes UnitedHealth, the largest U.S. health-insurer.

Caterpillar (NYSE:CAT) has lost 1.6% after the company announced that global retail machine sales dropped 4% during November, December, and January after falling just 1% in the three months ending in December. North American sales fell by 11%, while the Asia-Pacific region saw sales drop by 12%. Latin America increased by 3%, and the Europe, Africa, and Middle East region rose by 1%.

Shares of JPMorgan Chase (NYSE:JPM) are down 0.9% after a group of investors filed a proposal to split the CEO and chairman positions. Jamie Dimon currently holds both positions, but some investors believe he is unable to restore confidence in the bank and ensure future regulatory compliance. These concerns stem from the London Whale scandal and regulatory sanctions the company has faced in recent months. Shareholders will vote on the proposal in May during the company's annual shareholder meeting.

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