The outlook has shortly soured for India’s $433 billion banking sector after a uncommon selloff in HDFC Bank Ltd., the nation’s largest personal sector lender.

A gauge of the nation’s high 12 largest banks is ready for its worst week since September, erasing practically $21 billion in market worth by way of Thursday’s shut. Two thirds of that bruising loss got here from HDFC Bank, whose quarterly numbers confirmed falling internet curiosity margins and weaker deposit development.