Equity benchmark indices settled on a flat note in a volatile session on August 23 as the market sentiment was cautious ahead of the US Fed Chair Jerome Powell’s speech at the Jackson Hole Symposium. The BSE Sensex gained 33.02 points or 0.04 per cent to close at 81,086.21. The NSE Nifty was up 11.70 points or 0.05 per cent to settle at 24,823.20.