S&P Dow Jones Indices, the company that produces the S&P 500 stock index as well as myriad other benchmarks, is planning to launch a bond index – the S&P 500 Bond Index – in early July that will track the debt of the S&P 500 components.

The bond index, which will carry a traditional market weighting, will track debt issuance from 430 of the equity index's 500 members, comprising about $3 trillion in debt outstanding, with a market value of $3.8 trillion. "It's a significant portion of the corporate bond market," JR Rieger, managing director and global head of fixed income indices at S&P, said. Also, the data for the bond index will be live throughout the US business day, just like the stock index, unlike other bond indexes that provide only closing levels.