No explicit capital requirement that I am aware of - but would say the implicit capital requirement is that required to obtain the intended credit ratings for the bond tranches (eg. AAA, BB and junk), and those imposed by the buyers of the SPV's securities - i.e. the SPV needs to holds enough capital so investors are willing to buy its securities.
Capital for the SPV could be specified as the stream of cashflows transferred into the SPV rather than capital in the traditional sense of the word - so would rather describe it as collateralisation. SPV's are generally over collateralised (particularly on the AAA tranche) to ensure any individual failures in the underlying mortgage pool doesn't impact on the tranche.
If a sufficient number of mortgages fail, the whole thing falls flat. If the junk tranche was taken on by the bank setting up the SPV, the mortgage failures will hit the bank's own books and large asset losses occur (the kind that hits the evening news & severly impacts on share prices).
Last edited by a moderator: Mar 25, 2008