Which tokenized T-bill or yield fund actually pays what it promises
Signed basis-point deviation between the APY each tokenized U.S. Treasury advertises and the yield the smart contract actually distributes on-chain, measured over 30 days.
Every tokenized U.S. Treasury on the market publishes an APY. Ondo USDY, Superstate USTB, Ondo OUSG, Maple SyrupUSDC, each advertises a yield on its public dashboard. This page measures what they actually pay their token holders on-chain, using each issuer's own distribution mechanism (daily rebase, monthly USDC dividend, on-chain NAV oracle, or ERC-4626 share price), and compares it to the advertised number. The delta in basis points, sign preserved, is the honest read on whether the tokenized wrapper delivers what the marketing page claims. Every measurement traces back to an on-chain event and a citable issuer disclosure. No opinion, just the two numbers side by side. BlackRock BUIDL and Franklin BENJI are on the roadmap but currently paused: measurement methodology for each is not yet accurate (see FAQ).
Methodology
For each tokenized T-bill in the cohort we compute the delivered yield over a 30-day rolling window from the issuer's own on-chain distribution mechanism, then compare to the promised APY published on the issuer's official dashboard. Deviation is expressed in basis points with sign preserved: negative means the token paid less than advertised over the window, positive means more. The three distribution mechanisms measured are rebase (USDY), monthly USDC dividend transfers (USTB) and NAV appreciation via on-chain oracle (OUSG) or ERC-4626 vault share price (SyrupUSDC). Windows: 30-day rolling annualized as the headline, plus 7d and lifetime for volatility context. BUIDL and BENJI are not yet active: BUIDL's distributor mints conflate new subscriptions with yield; BENJI's Ethereum wrapper exposes no on-chain NAV.
Frequently asked
Why does the delivered yield sometimes differ from the advertised APY?
Three main reasons. First, distribution timing: dividend-style tokens like USTB accrue yield daily but pay it monthly, so a 30-day window that starts mid-cycle undersamples. Second, weekend and holiday accrual: U.S. Treasuries do not yield on Saturdays, Sundays or federal holidays, so a naive calendar-day annualization differs from the SEC's own convention. Third, management-fee timing: fees are accrued daily but recognized at the fund level on different schedules, which can create a 5 to 30 bps short-window gap even when the annual net yield matches the advertised APY exactly.
Which distribution model is the most transparent?
Rebase, exemplified by USDY. Delivered yield is a pure function of totalSupply at t=now versus t=window ago, both readable on-chain by anyone. Dividend-style (USTB) is one step less transparent: delivered yield sums USDC Transfer events from the treasury wallet, which requires knowing the treasury address (documented here). NAV-style (OUSG) is the least on-chain-native: the daily NAV is set by the fund manager off-chain and posted daily; a delayed NAV update looks like a yield gap even when the underlying portfolio is fine. SyrupUSDC sits between: its ERC-4626 convertToAssets share price is fully on-chain but the underlying loan book is off-chain.
Where does the promised yield come from?
From each issuer's own public dashboard or fund fact sheet, refreshed at least weekly. Each entry in the harness config logs the source URL and the date the value was last read. When an issuer updates the advertised APY, the change is picked up on the next config reload.
Can this benchmark tell me if an issuer is misrepresenting yield?
No. It tells you how the delivered yield tracks the advertised yield over a specific window. A persistent negative deviation is a signal worth investigating, but the cause can be timing, methodology, weekend conventions or fee schedules. This bench provides the number; investors and regulators can investigate the cause with the issuer directly.
Why are BUIDL and BENJI not in the cohort?
Both are dormant pending harness improvements. BUIDL (BlackRock) uses a Securitize distributor that mints additional BUIDL shares rather than transferring USDC, so the dividend-Transfer model reports zero and conflates new subscriptions with yield. Separating the two requires cross-referencing Securitize's monthly distribution announcements, which is on the roadmap. BENJI (Franklin Templeton) primarily lives on Stellar; its Ethereum wrapper exposes no on-chain NAV function, and Franklin has not yet published a machine-readable JSON endpoint. Outreach was sent to Franklin's digital assets team; the probe activates once an endpoint is confirmed.
Why don't you include DAI, USDS, sUSDe or other yield-bearing stablecoins?
This bench is scoped to tokenized U.S. Treasury and money-market funds where an off-chain issuer publishes a specific advertised APY that can be compared to delivered yield. Yield-bearing stablecoins backed by CDP interest, LSTs or perp funding are a different question with a different measurement contract; they may join a sibling bench later.
Source code github.com/ChainBench/OpenChainBench/tree/main/harnesses/rwa-yield-accuracy