Under the CRR, the capital charge for a single A non-senior STS tranche is the same as for BB corporate risk. So does the market regard these are being similarly risky? No: capital charges for non-senior STS and for non-STS remain discouragingly high. AFME notes that the capital charge for a AAA senior tranche of a 30 year RMBS with an 80% LTV will be 5% (and more for the non-senior piece of course), whereas the capital charge if an insurer instead buys the assets in the RMBS pool themselves, the capital charge for the entire pool is only 3%. Will the EC listen?