Underlying Asset

The underlying asset is the foundational concept for understanding RWA, tokenized real-world assets. The token is the on-chain representation; the underlying is what exists in the real world or on the issuer's books. The link is set by a legal structure, usually an SPV, a trust or a custody agreement, so that holding the token confers an economic or legal right over the asset. A custodian holds the real asset, and audits or proof-of-reserve verify that it exists and backs the issued tokens. The critical parameter is the ratio, usually 1:1, between tokens outstanding and underlying units backed.

A token is only worth what its underlying is worth, and what can be claimed from it. The quality, liquidity, custody and verifiability of that asset determine the token's real risk. That is why two tokens that look alike can differ sharply depending on what backs them and with what rights.

Concrete examples: the underlying is US Treasury bills in funds such as BlackRock BUIDL or Franklin FOBXX; it is custodied physical gold in gold tokens like Paxos's PAXG; and it is USD or equivalent reserves in stablecoins like Circle's USDC. Its value is measured via NAV in funds or via market price, its backing is collateralization, and the reliability of its claim against the issuer is counterparty risk. When the underlying is a security, it is wrapped with compliance-by-design.