The Sensex opened with a positive gap of 316 points at 17,265, and rallied to a high of 17,586. The index is now up 588 points to 17,537.The NSE Nifty has rallied 182 points to 5,111.All Sensex stocks are in positive zone.BHEL has zoomed 6% to Rs 2,098. Hindalco has soared 4.7% to Rs 157, and Reliance Energy has surged 4.4% to Rs 1,626.Hindustan Unilever and Reliance have rallied over 4% each to Rs 201 and Rs 2,483, respectively.Reliance Communications, ONGC and HDFC Bank have advanced 3.7% each to Rs 579, Rs 979 and Rs 1,520, respectively.Bharti Airtel, Mahindra & Mahindra, ICICI Bank and NTPC have gained around 3.5% each at Rs 888, Rs 597, Rs 1,137 and Rs 194, respectively.