Trading in corporate debt securities at leading stock exchanges NSE and BSE has surged 66.5 per cent to a record Rs 4.34 lakh crore during the first quarter of the current financial year, according to official data. Trading worth Rs 2.61 lakh crore in corporate bonds was seen on the two bourses during the April-June period of 2016-17, according to data compiled by capital markets regulator Sebi.