For synthetic securitisations, the effect of applying CRM techniques for hedging the underlying exposure are treated according to chapter CA-4. In case there is a maturity mismatch, the capital requirement will be determined in accordance with paragraphs CA-4.6.1 to CA-4.6.4. When the exposures in the underlying pool have different maturities, the longest maturity must be taken as the maturity of the pool. Maturity mismatches may arise in the context of synthetic securitisations when, for example, a bank uses credit derivatives to transfer part or all of the credit risk of a specific pool of assets to third parties. When the credit derivatives unwind, the transaction will terminate. This implies that the effective maturity of the tranches of the synthetic securitisation may differ from that of the underlying exposures. Originating banks of synthetic securitisations must treat such maturity mismatches in the following manner. A bank applying the standardised approach for securitisation must deduct all retained positions that are unrated or rated below investment grade. A bank applying the IRB approach must deduct unrated, retained positions if the treatment of the position is deduction specified in paragraphs CA-6.4.51 to CA-6.4.88. Accordingly, when deduction is required, maturity mismatches are not taken into account. For all other securitisation exposures, the bank must apply the maturity mismatch treatment set forth in paragraphs CA-4.6.1 to CA-4.6.4.