From legal wrappers to the biggest RWA category
In Part 1 of this series we walked through the mechanics of taking a real-world asset on-chain: the legal wrapper, the transfer agent, the oracle, the redemption rail. This part picks one asset class and shows what happens when those mechanics actually meet a deep, liquid market. Tokenised US Treasuries are the cleanest case study in crypto: by 29 April 2026 the segment had crossed $15 billion in on-chain assets, and the top five products controlled roughly 68% of it.
The reason is unromantic. Holding T-Bills directly, in size, is operationally annoying. Holding a token that represents a share in a fund that holds T-Bills is a transfer. So once the legal plumbing existed, demand piled in: treasuries, market makers, DAOs, stablecoin issuers, and now lending protocols. The Fed funds band sits at 3.50–3.75% as of May 2026, and the 4-week T-Bill printed 3.66% on 5 May. That is the yield this entire $15B layer is passing through, in slightly different wrappers, to slightly different audiences.
Let's walk the products.
BUIDL: the institutional reserve asset
BlackRock's USD Institutional Digital Liquidity Fund — BUIDL — launched on Ethereum on 20 March 2024 with Securitize as transfer agent and BNY Mellon as custodian. The fund is a Reg D 506(c) offering: qualified purchasers only, $5 million minimum. Two years later it sits around $2.5–2.9 billion AUM and is live across nine chains.
Retail will never touch BUIDL directly, and that is fine, because BUIDL has quietly become the reserve asset of the on-chain economy. Three integrations matter:
- Ethena's USDtb, a yield-bearing stablecoin with roughly $1.5B circulating in 2026, holds BUIDL as its primary reserve.
- Ondo's OUSG uses BUIDL's same-day USDC redemption rail to give its own holders intraday liquidity.
- Aave's GHO stablecoin and the Aave Horizon RWA market accept BUIDL-adjacent collateral; Horizon alone has more than $176M in outstanding loans as of 2026.
If you have used a yield-bearing dollar in DeFi recently, there is a non-trivial chance the dollar in question is, two layers down, a share of BUIDL. That same-day USDC redeemer — boring on paper — is the piece of plumbing that lets all of this work. Without it, every protocol on top would have T+1 settlement risk; with it, redemption looks like a normal stablecoin swap.
Franklin Templeton FOBXX (BENJI): the regulated retail option
Franklin Templeton's FOBXX, accessed through the BENJI app, is the opposite end of the spectrum. It is a registered '40 Act money-market fund — the same legal structure as the funds inside any US brokerage sweep account — and it was the first US-registered fund to record share ownership on a public blockchain, going live on Stellar in April 2021 before expanding to Polygon, Solana, Base, Aptos, Avalanche, Arbitrum and Ethereum.
Numbers as of 29 April 2026: $1.98B AUM, $20 minimum, and since May 2025, peer-to-peer transfers between BENJI users are open. That last point matters more than it sounds. A '40 Act fund whose shares can move directly between wallets, 24/7, without a broker in the loop, is genuinely new. WisdomTree's WTSYX and WTGXX went a step further in February 2026 when the SEC approved them for 24/7 fixed-$1 intraday trading — a money-market fund that behaves, on-chain, like a stablecoin.
If you are a US retail user who wants T-Bill yield without leaving the regulatory perimeter, BENJI and the WisdomTree funds are the answer. The yield is a touch lower than the raw T-Bill rate after fees, but the wrapper is one your accountant already understands.
Ondo: USDY for the rest of the world, OUSG for institutions
Ondo Finance runs two distinct products and it is worth keeping them straight.
USDY is a tokenised note issued from a Bermuda SPV, structured for non-US investors. After a 40–50 day initial lock-up, USDY is permissionless: it transfers freely on nine chains and trades in DeFi like any other ERC-20. AUM is north of $1B. The yield accrues into the token price (or via a rebasing variant), so holding USDY in a wallet feels identical to holding any yield-bearing stablecoin — but the issuer is not a stablecoin issuer, the wrapper is a note, and US persons cannot hold it.
OUSG is the institutional cousin: roughly $692M TVL, around 3.49% APY as of January 2026, qualified-purchaser only, and crucially wired into BUIDL's same-day USDC redemption rail. OUSG is what you buy if you are a treasury or fund that needs T-Bill exposure with intraday liquidity and a US-compliant wrapper.
Ondo also launched Ondo Chain, a permissioned RWA-focused L1, in February 2025. Whether dedicated RWA chains win over general-purpose L1s and L2s is one of the more interesting open questions in this corner of the market — Part 6 of this series will return to it.
USYC, USTB, and the second tier
Below the big three sit a cluster of products that are less famous but increasingly load-bearing.
USYC is the tokenised money-market product originally built by Hashnote. Circle acquired Hashnote on 21 January 2025 in a deal valued at $1.52B at announcement, and USYC is now positioned as a yield engine sitting next to USDC. The strategic logic is obvious: a stablecoin issuer that also owns a tokenised T-Bill product can offer a yield-bearing companion token without leaving the building.
USTB is Superstate's tokenised short-Treasury fund, with roughly $950–967M AUM by March 2026. The notable event came on 24 March 2026, when Invesco took over portfolio management of USTB — the first Big-Three asset manager to operate a tokenised on-chain Treasury product directly. That is a meaningful signalling moment: tokenisation is no longer a thing crypto-native firms do that traditional managers watch from a distance.
For non-US users who want SEC-registered ETF exposure rather than a fund wrapper, Backed Finance's bIB01 and bIBTA are Swiss DLT-Act tracker certificates over iShares short-Treasury ETFs. They are not the cheapest option, but they are the cleanest way to hold an existing iShares product on-chain with a recognisable Swiss legal wrapper.
Which product for which user
The honest answer depends on three things: where you live, how much you have, and what you want to do with the token.
- US retail with under $1M: BENJI (FOBXX) or the WisdomTree funds. Registered, low minimums, regulated.
- Non-US retail or DAO treasury: USDY. Permissionless after lock-up, deep DeFi integration, transparent reporting.
- US institution with a treasury function: OUSG or USTB. Same-day liquidity, qualified-purchaser wrapper.
- Stablecoin issuer or large protocol: BUIDL or USYC. Reserve-grade, custody-grade, designed to back another token.
- DeFi user wanting T-Bill yield as collateral: USDY or USDtb on-chain; check that the lending market actually accepts the token before depositing. The fundamentals of how that collateral behaves in a liquidation are covered in our piece on on-chain lending and liquidations.
A word of caution that the marketing pages will not give you. Tokenised T-Bills are not stablecoins. They carry interest-rate risk (small, given the short duration), credit risk on the issuer and custodian (small, but non-zero), and smart-contract risk on whichever chain you hold them. If you are using one as a savings vehicle, fine. If you are using one as a 1:1 dollar substitute, read our explainer on stablecoin design first and understand what you are actually holding. And if you have not done the basics on wallet hygiene and approvals, do that before parking real money in any of this.
What the $15B layer actually unlocks
The interesting story is not the headline number. It is the second-order effect: T-Bill tokens have become the reserve and collateral layer that the next generation of dollar products is being built on. USDtb is backed by BUIDL. Ondo's stablecoin strategy runs through OUSG. Aave Horizon is lending against tokenised funds. Circle owns USYC. Invesco runs USTB. The legal regime around all of this is still being written — we cover the US side in our piece on the stablecoin framework rolling out in 2026 — but the technical infrastructure is, at this point, real.
T-Bills were the easy asset to tokenise: liquid, dollar-denominated, low-credit-risk, with a redemption mechanic that maps cleanly to on-chain primitives. The harder question is what happens when the same plumbing is pointed at credit risk you cannot redeem on demand.
Next in Part 3: tokenised private credit — Maple, Centrifuge, Goldfinch and the harder economics of putting illiquid loans on-chain.
