Investors remained cautious ahead of the state election exit poll results to be announced immediately after voting in Rajasthan and Telangana on Friday evening. Nifty Pvt Bank was the top gainer on Friday among all sectoral indices ahead of exit polls, closing at 15062.25 with a gain of 2.11 per cent. After opening with an upside gap, the index managed to make series of higher highs throughout the day.