The Sensex continues to exhibit firm trend, and is now up 639 points to 17,588.The NSE Nifty has rallied 189 points to 5,119.BHEL has zoomed nearly 8% to Rs 2,137. Hindalco has soared 7% to Rs 161, and DLF has surged 6.6% to Rs 869.ICICI Bank and Hindustan Unilever have rallied nearly 6% each to Rs 1,164 and Rs 204, respectively.Reliance Energy and Reliance Communications have advanced around 5.5% each to Rs 1,645 and Rs 589, respectively.HDFC Bank, Larsen & Toubro and Reliance have gained around 5% each at Rs 1,543, Rs 3,436 and Rs 2,501, respectively.NTPC has moved up 4.5% to Rs 196, and ONGC has added nearly 4% to Rs 981.Ambuja Cements, down nearly 1%, is the sole loser at Rs 115.Out of 2,539 stocks traded so far, 1,655 have advanced, 844 have declined and 40 are unchanged.