Due to the credit market disruption, Fitch Ratings says it is re-examining its rating methodology for all market value structures.

“Ongoing dislocations in the credit markets are placing unprecedented stresses on liquidity and market prices, even for assets that are not credit impaired. This, in turn, is impacting ratings for many market value structures such as SIVs, CPDOs, Leveraged Super Senior and Market Value CDOs, among others,” the rating agency reports.

As a result, Fitch is re-examining its rating methodology for all market value structures. Today, it published an exposure draft for comment, Fitch is proposing revised liquidity stresses for most market value structures, which in turn would lead to higher credit enhancement levels, as well as ratings ‘caps’ for certain less liquid assets and for certain structures.

Additionally, Fitch is advocating greater transparency for investors in the structured finance markets through enhanced disclosure and the addition of various deterministic stresses that capture and highlight the risks of extreme, ‘fat tail’ events.

“Structural changes in the credit markets and the dispersion of risk through leveraged structured vehicles has made it more difficult for investors to gauge volatility in times of stress and, therefore, Fitch is calling for greater transparency and revisiting its criteria in light of recent events,” said Derivative Fitch chief credit officer, Roger Merritt. “We believe this proposal is an important step toward meeting the needs of investors and bringing enhanced stability to the ratings on these securities.”

Under the new proposed framework, ratings would be capped at ‘A’ for less liquid, more complex assets or those for which future liquidity and price volatility is uncertain. For more liquid assets, Fitch expects to continue assigning ratings as high as ‘AAA’ to traditional MVS. However, credit enhancement will likely increase, perhaps significantly, to take into account the most recent market stresses and incorporate the ratings impact of more extreme periods of volatility and illiquidity. Of critical importance, particularly at the highest rating levels (‘AA’ and ‘AAA’) is the ability to comfortably assess asset liquidity and overcollateralization levels, taking into consideration how markets may perform under future stresses.

After the comment period, Fitch will introduce formal ratings criteria. The comment period is until the end of January.