Insurance companies that insure their own insurance books invariably do so through reinsurance. Just like insurance, a reinsurer will guarantee to cover the insurance losses of the reinsured insurance company above an agreed amount in return for a fee. Reinsurers can and do transfer reinsurance risk to institutional investors via structured products. In the case of car or home insurance, a reinsurer will reinsure an insurer’s whole book of business on the understanding that all primary insurance is underwritten using standard terms and conditions. For large-scale insurance risk such as catastrophe risk, a reinsurer will assess terms of individual primary insurance contracts before agreeing to reinsure.