A consortium of Wall Street securities dealers has launched a new investment vehicle backed by bonds issued by some of the subprime market’s largest players. “We expect [the index] to build liquidity and transparency in the synthetic asset-backed market, attracting global investors that seek exposure to this asset class, both on the buy-side and sell-side,” said Kevin Gould, executive vice president and head of data products at Markit, a derivative management and pricing firm,