Cap is a credit platform built on the Ethereum blockchain and supported by financial guarantees. Each loan is underwritten through custodial collateral to protect the rights of the lender. The platform relies on an Underwriter market, which independently initiates and provides guarantees for US dollar loans. The insurer invests its own capital in every allocation decision and obtains underwriting premium from credit spreads. Lenders can earn secure returns guaranteed by the underwriter's collateral, with all risk protections transparent and enforceable through smart contracts.