Equity benchmark Sensex ended on a flat note after scaling the 53,000 mark on Tuesday as investor booked profits at higher levels. After touching a lifetime intra-day peak of 53,057.11, the 30-share BSE index settled 14.25 points or 0.03 per cent higher at 52,588.71. Similarly, the broader NSE Nifty rose 26.25 points or 0.17 per cent to 15,772.75.