Selloff in HDFC twins drives Sensex 400 points lower, Nifty below 18,200

In the Sensex pack, HDFC and HDFC Bank were the top laggards, falling over 4% each as the merger of both companies may result in slight outflows of $150 to 200 million. IndusInd Bank, Tata Steel, Bajaj Finance and Asian Paints also opened in the red.