(91)In order to ensure that the risks arising from securitisation positions are appropriately reflected in the capital requirements of insurance and reinsurance undertakings, it is necessary to include rules providing for a risk-sensitive and prudentially sound treatment of such investments, depending on the nature and underwriting process of underlying exposures, and structural and transparency features. Securitisations that meet those requirements should be subject to a specific treatment in the spread risk sub-module, recognising their lower risk profile. Given that only the most senior tranches qualify for such a treatment, and taking into account the credit enhancement embedded in most senior tranches compared to the whole pool of underlying exposures, it is appropriate to cap the spread risk factors on such positions at the level of the spread risk factor that would be applicable to underlying exposures, namely at the level of the 3 % risk factor per year of duration applicable to unrated loans. This approach should be re-examined as part of the Commission review of the methods, assumptions and standard parameters used when calculating the Solvency Capital Requirement with the standard formula, as referred to in recital (150).