Which tokenized T-bill or yield fund actually pays what it promises
How far the yield each tokenized U.S. Treasury actually distributes on-chain sits from the APY it advertises, in basis points over 30 days; the closest tracker ranks first, and the signed gap (paid less or more than promised) is the column beside it.
TL;DR. As of , USDY and USTB both post the lowest yield deviation, tied at 14.0 bps (30d avg) across 4 ranked tokens. Source: OpenChainBench, https://openchainbench.com/benchmarks/rwa-yield-accuracy.
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, as the growth of each token's NAV read from the issuer's own oracle, Chainlink feed or ERC-4626 share price, and compares it to a dated reference APY (the 30-day mean on a public yields feed, the same window as the measurement). The gap in basis points, closest first, with the sign in the next column, 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 as a reference: the 30-day mean APY on the DefiLlama yields feed for every token, read by hand and dated, the issuer's own displayed figure kept in the notes. The headline is the absolute gap in basis points, closest first; the signed gap sits beside it, negative when the token paid less than advertised over the window, positive when more. Every live token is measured the same way, as NAV appreciation: Ondo's on-chain oracle for USDY and OUSG, Superstate's Chainlink NAV feed for USTB, the ERC-4626 share price for SyrupUSDC. Windows: 30-day rolling annualized as the headline, 7-day beside it. 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.
Results: 4 tokens ranked by Yield deviation (30d avg)
Frequently asked
Why does the delivered yield sometimes differ from the advertised APY?
Three main reasons. First, the advertised figure's window: an issuer quotes a 7-day SEC yield or a spot APY while the bench realizes 30 days, so a rate move inside the month opens a gap that closes as the window rolls. 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?
The ERC-4626 share price (SyrupUSDC): convertToAssets is computed by the vault contract from its own accounting, readable by anyone, though the underlying loan book is off-chain. An issuer oracle or Chainlink NAV feed (USDY, OUSG, USTB) is one step less native: the daily NAV is set by the fund administrator off-chain and posted on-chain, so a delayed update looks like a yield gap even when the portfolio is fine. A pure rebase read would be the most native of all, but USDY's multi-chain supply makes it unusable on Ethereum (see the findings).
Where does the promised yield come from?
From one source for every row: the 30-day mean APY on the DefiLlama yields feed, read by hand and dated per entry in the harness config, with the issuer's own displayed APY kept in the notes where a page is readable. A 30-day reference against a 30-day delivered yield keeps the window out of the deviation; the readings are refreshed best effort (2026-07-22, then 2026-09-23), so a stale reference can still be the curation lagging a rate move rather than the issuer.
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