Editor's Note: TheStreet ratings do not represent the views of TheStreet's staff or its contributors. Ratings are established by computer based on metrics for performance (which includes growth, stock performance, efficiency and valuation) and risk (volatility and solvency). Companies with poor cash flow or high debt levels tend to earn lower ratings in our model All three major indices are trading down today with the Dow Jones Industrial Average ( ^DJI) trading down 175 points (-1.2%) at 14,582 as of Wednesday, April 17, 2013, 12:45 PM ET. The NYSE advances/declines ratio sits at 512 issues advancing vs. 2,465 declining with 93 unchanged. The Health Care sector currently sits down 1.45 versus the S&P 500, which is down 1.75. On the negative front, top decliners within the sector include Sanofi ( SNY), down 3.81, Regeneron Pharmaceuticals ( REGN), down 3.15, Novartis ( NVS), down 2.67, Amgen ( AMGN), down 2.05 and Novo Nordisk A/S ( NVO), down 1.73. TheStreet Ratings group would like to highlight 5 stocks pushing the sector lower today: 5. Aetna ( AET) is one of the companies pushing the Health Care sector lower today. As of noon trading, Aetna is down $1.48 (-2.6%) to $55.16 on average volume Thus far, 1.3 million shares of Aetna exchanged hands as compared to its average daily volume of 3.4 million shares. The stock has ranged in price between $54.98-$56.35 after having opened the day at $56.33 as compared to the previous trading day's close of $56.64. Aetna Inc. operates as a diversified health care benefits company in the United States. The company operates in three segments: Health Care, Group Insurance, and Large Case Pensions. Aetna has a market cap of $18.0 billion and is part of the health services industry. The company has a P/E ratio of 11.5, below the S&P 500 P/E ratio of 17.7. Shares are up 22.3% year to date as of the close of trading on Tuesday. TheStreet Ratings rates Aetna as a buy. The company's strengths can be seen in multiple areas, such as its revenue growth, attractive valuation levels, good cash flow from operations, largely solid financial position with reasonable debt levels by most measures and solid stock price performance. We feel these strengths outweigh the fact that the company has had sub par growth in net income. Get the full Aetna Ratings Report now. Exclusive Offer: Jim Cramer's 'go-to' small/mid-cap guru Bryan Ashenberg only buys stocks he thinks could return 50-100%. See his top picks for 14-days FREE.