The S&P BSE Sensex and NSE Nifty 50 indexes closed at all-time highs on Monday led by gains in ICICI Bank, Larsen & Toubro, Kotak Mahindra Bank, ONGC and Tata Consultancy Services. The benchmarks staged a gap up opening wherein Sensex rose as much as 274 points to hit record high of 46,373 and Nifty 50 index touched an all-time high of 13,597.50.