Indian companies have raised about Rs 1.75 lakh crore by issuing bonds through private placement on BSE's electronic book mechanism since its launch last July, Asia's oldest bourse chief Ashishkumar Chauhan said on Tuesday. In comparison, companies raised around Rs 10,000 crore from rupee-denominated bonds, also called masala bonds, in the last 1-2 years, he added. "Investors have evolved to a great extent and are now more receptive and open to diversification into new assets class," Chauhan said at a conference on bond market organised by industry body Assocham here.