New Delhi, March 22 -- The combined market valuation of five of the top-10 most-valued firms eroded by Rs.1 lakh crore last week, with HDFC Bank taking the biggest hit.

Last week, the BSE benchmark Sensex dipped 30.96 points, or 0.04 per cent, and the NSE Nifty slipped 36.6 points, or 0.15 per cent.

"Markets ended the week on a largely flat note with a negative bias, reflecting underlying caution among participants. The tone remained positive during the first three sessions; however, a sharp decline on Thursday erased the gains, followed by a volatile final session," Ajit Mishra, SVP, Research, Religare Broking Ltd, said.

While HDFC Bank, ICICI Bank, Tata Consultancy Services (TCS), Bajaj Finance and Hindustan Unilever were the laggard...