Editor's Note: Any reference to TheStreet Ratings and its underlying recommendation does not reflect the opinion of TheStreet, Inc. or any of its contributors including Jim Cramer or Stephanie Link. All three major indices are trading down today with the Dow Jones Industrial Average ( ^DJI) trading down 41 points (-0.3%) at 14,800 as of Friday, Aug. 30, 2013, 12:50 PM ET. The NYSE advances/declines ratio sits at 850 issues advancing vs. 2,040 declining with 117 unchanged. The Basic Materials sector currently sits down 0.4% versus the S&P 500, which is down 0.3%. On the negative front, top decliners within the sector include Barrick Gold Corporation ( ABX), down 2.2%, Total ( TOT), down 1.4%, Petroleo Brasileiro SA Petrobras ( PBR), down 1.2%, Royal Dutch Shell ( RDS.A), down 1.1% and BP ( BP), down 0.6%. TheStreet would like to highlight 5 stocks pushing the sector lower today: 5. Ecopetrol S.A ( EC) is one of the companies pushing the Basic Materials sector lower today. As of noon trading, Ecopetrol S.A is down $0.36 (-0.8%) to $45.03 on light volume. Thus far, 125,444 shares of Ecopetrol S.A exchanged hands as compared to its average daily volume of 386,100 shares. The stock has ranged in price between $44.71-$45.58 after having opened the day at $45.36 as compared to the previous trading day's close of $45.39. Ecopetrol S.A., an integrated oil company, engages in the exploration, development, and production of crude oil and natural gas Colombia. The company operates in four segments: Exploration and Production, Refining and Petrochemicals, Transportation, and Market and Supply. Ecopetrol S.A has a market cap of $94.6 billion and is part of the energy industry. Shares are down 22.9% year to date as of the close of trading on Thursday. Currently there are no analysts that rate Ecopetrol S.A a buy, 2 analysts rate it a sell, and 1 rates it a hold. TheStreet Ratings rates Ecopetrol S.A as a buy. The company's strengths can be seen in multiple areas, such as its good cash flow from operations, expanding profit margins and largely solid financial position with reasonable debt levels by most measures. We feel these strengths outweigh the fact that the company has had lackluster performance in the stock itself. Get the full Ecopetrol S.A Ratings Report now. STOCKS TO BUY: TheStreet Quant Ratings has identified a handful of stocks that can potentially TRIPLE in the next 12-months. Learn more.