India, March 20 -- Shares of HDFC Bank dived over 5 per cent on Thursday after Atanu Chakraborty resigned as chairman of the country's second biggest lender, citing ethical concerns.The blue-chip stock tumbled 5.13 per cent to settle at INR 799.70 on the BSE, trimming some of its sharp early losses. During the day, it tanked 8.41 per cent to INR 772 - its 52-week low.

At the NSE, the stock dropped 5.31 per cent to close at INR 798.20. Intra-day, it dived 8.66 per cent to hit the 52-week low of INR 770.The company's market valuation eroded by INR 65,946.08 crore to INR 12,30,896.85 crore following the sharp decline in the stock.

In the equity market, the 30-share BSE Sensex tanked 2,496.89 points or 3.26 per cent - its biggest single-day...