As of the latest update, the Stablecoin Yield Index (SYX) stands at 3.41%. The Stablecoin Yield Index (SYX) is a TVL-weighted benchmark for conservative USDC yield across the largest onchain lending markets on Ethereum, Base, and Arbitrum. SYX is computed directly from canonical smart contracts — not aggregated from third-party APIs such as DeFiLlama or CoinGecko. SYX aggregates eight onchain components into a single reference rate: the Aave v3 USDC supply markets on Ethereum, Base, and Arbitrum; the Compound v3 USDC supply market on Ethereum; and curated Morpho v2 Prime USDC strategies from Steakhouse Financial and Gauntlet on Ethereum and Base. Each component’s weight equals its live total value locked as a share of the combined TVL of all participating components, recomputed on every poll, so the index reflects where USDC capital actually sits. Aave v3 and Compound v3 markets expose a live supply rate that is queried directly onchain; the Morpho v2 vault contracts maintain a share price that reflects accrued interest, from which SYX computes realized yield over a measurement window that begins at six hours and widens to seven days. On each chain, Steakhouse and Gauntlet Prime USDC vault deposits are combined into a single weight per chain. The index updates every 15 minutes and is engineered for resilience: if any source becomes unreadable its TVL weight is renormalized across the remaining sources, each reading passes a sanity check against the last known good value, and a last-known-good fallback ensures the index never displays a broken number. SYX excludes structurally distinct, higher-risk products such as synthetic dollar exposure (e.g. Ethena) and private credit strategies. Because it queries the protocol contracts themselves, SYX is not exposed to any third party’s outages, rate limits, methodology changes, or errors, and its methodology is transparent and independently reproducible. The live value and full methodology are available as machine-readable JSON at https://accrue.cc/api/index and https://accrue.cc/api/index/methodology.