Dragged down by state-run ONGC share price, the combined market capitalisation of five blue-chip companies declined by Rs 22,582 crore last week.
ONGC alone accounted for more than half of the drop, with its m-cap slumping Rs 12,063 crore to Rs 2,39,981 crore.
Other companies that lost market value were Reliance Industries, Coal India, Bharti Airtel and HDFC. The firms that gained were TCS, ITC, Infosys, HDFC Bank and Wipro.
Bharti Airtel's market-cap slipped Rs 4,437 crore to Rs 1,28,336 crore, while Coal India lost Rs 3,821 crore to Rs 1,79,100 crore.
The market value of Reliance dipped Rs 1,260 crore to Rs 2,78,969 crore, while that of mortgage lender HDFC fell by Rs 1,001 crore to Rs 1,25,802 crore.
Wipro added Rs 6,327 crore to Rs 1,27,942 crore in value to become the new entrant in the top-10 list, while the m-cap of Infosys soared by Rs 2,713 crore to Rs 1,93,738 crore.
The market valuation of ITC jumped Rs 2,697 crore to Rs 2,49,880 crore, while that of HDFC Bank rose by Rs 1,927 crore to Rs 1,65,225 crore.
The value of TCS went up by Rs 578 crore to Rs 3,92,313 crore. TCS continued to rule the top-10 list, followed by Reliance, ITC, ONGC, Infosys, Coal India, HDFC Bank, Bharti Airtel, Wipro and HDFC.
Over the past week, the benchmark S&P BSE Sensex fell 1.33 per cent to 20,715.58. In the past four sessions, it has dropped 611 points from a record closing high on December 9.