Equity benchmark indices rebounded sharply on Wednesday after an eight-day slump, with the Sensex jumping 715.69 points, helped by buying in bank and financial stocks after the RBI left key interest rates unchanged and revised upward its growth estimates for the current fiscal to 6.8 per cent.Photograph: Francis Mascarenhas/ReutersThe 30-share BSE Sensex jumped 715.69 points or 0.89 per cent to settle at 80,983.31.During the day, it surged 800.81 points or 0.99 per cent to 81,068.43. The 50-share NSE Nifty ...