FXStreet (Mumbai) - The stock markets in the US are trading on a flat note as investors await a speech from Federal Reserve Chair Janet Yellen. At the time of writing, the Dow Jones Industrial Average (DJIA) was trading 4 points lower at 17,883. The S&P 500 was largely unchanged, while the Nasdaq was up 14 points. Among the DJIA stocks, United Health was up 2.38%, followed by a 1.14% rise in Microsoft. The losing side included Exxon Mobil; down 0.58%. Yellen will address the Economic Club of Washington in the early afternoon, with investors looking out for further hints regarding the much awaited liftoff. For more information, read our latest forex news.