The reviews were prompted by former Chairman Atanu Chakraborty’s dramatic March 18 resignation, a decision he had said in a letter to the exchanges was prompted by alleged deviations ‘incongruent’ with his ethics and value systems. The reference to possible ethical transgressions at the country’s most-valued lender by Chakraborty, a former Secretary at the Department of Economic Affairs and a retired IAS officer, sent shockwaves through India’s banking establishment and caused an immediate slide in the stock.