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 32 points (-0.2%) at 17,036 as of Thursday, Sept. 11, 2014, 12:55 PM ET. The NYSE advances/declines ratio sits at 1,537 issues advancing vs. 1,470 declining with 140 unchanged. The Basic Materials sector currently sits down 0.3% versus the S&P 500, which is down 0.1%. On the negative front, top decliners within the sector include Air Products & Chemicals ( APD), down 2.2%, Statoil ASA ( STO), down 1.6%, Royal Dutch Shell ( RDS.B), down 1.0%, TransCanada ( TRP), down 0.9% and Chevron ( CVX), down 0.6%. Top gainers within the sector include Petroleo Brasileiro SA Petrobras ( PBR), up 1.2%, Williams Companies ( WMB), up 1.0% and Pioneer Natural Resources ( PXD), up 1.0%. TheStreet would like to highlight 3 stocks pushing the sector lower today: 3. Ecopetrol ( EC) is one of the companies pushing the Basic Materials sector lower today. As of noon trading, Ecopetrol is down $0.26 (-0.8%) to $33.96 on light volume. Thus far, 91,989 shares of Ecopetrol exchanged hands as compared to its average daily volume of 417,000 shares. The stock has ranged in price between $33.85-$34.38 after having opened the day at $34.18 as compared to the previous trading day's close of $34.22. Ecopetrol S.A., an integrated oil company, is engaged in the exploration, development, and production of crude oil and natural gas primarily in Colombia, Peru, Brazil, and the United States Gulf Coast. Ecopetrol has a market cap of $70.5 billion and is part of the energy industry. Shares are down 11.0% year-to-date as of the close of trading on Wednesday. Currently there is 1 analyst that rates Ecopetrol a buy, 3 analysts rate it a sell, and 1 rates it a hold. TheStreet Ratings rates Ecopetrol as a hold. The company's strengths can be seen in multiple areas, such as its revenue growth, attractive valuation levels and good cash flow from operations. However, as a counter to these strengths, we also find weaknesses including feeble growth in the company's earnings per share, deteriorating net income and disappointing return on equity. Get the full Ecopetrol 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.