Mumbai: Key Indian equity market indices opened in the green on Thursday despite a drop in the Asian markets and at the Wall Street ahead of the Federal Reserve Chair Janet Yellen's speech. The 30-scrip Sensitive Index (Sensex) was trading 74.43 points or 0.27 per cent up during the early session. The wider 51-scrip Nifty of the National Stock Exchange (NSE) was also trading 18.55 points or 0.21 per cent higher at 8,668.85 points. The BSE Sensex, which opened at 28,103.60 points, was trading at 28,134.37 points (at 9.16 a.m.) in the early session, higher 74.43 points or 0.27 per cent from the previous day's close at 28,059.94 points. The Sensex touched a high of 28,136.19 points and a low of 28,097.77 points in the trade so far.