When BlackRock launched its tokenized Treasury fund BUIDL in March 2024, Ondo Finance moved $95 million into it within the first week. That made Ondo the fund's largest holder and its first major crypto-native client, establishing a relationship that now underpins nearly $700 million in tokenized Treasury exposure through Ondo's OUSG product.
The integration solved a practical problem that had constrained tokenized Treasuries since Ondo first launched OUSG in January 2023. Understanding how these two products connect explains why Ondo commands the largest share of the tokenized securities market, and what it means for ONDO token holders.
From ETFs to BUIDL: Why Ondo Switched
OUSG originally held its backing assets in BlackRock's iShares Short Treasury Bond ETF (SHV), a traditional exchange-traded fund that only traded during U.S. market hours. This created a friction point that undermined the entire value proposition of tokenized Treasuries. Crypto markets operate around the clock, but OUSG redemptions were limited to when the underlying ETF could actually settle, typically taking T+2 days (two business days after the trade).
BUIDL changed the math. BlackRock's USD Institutional Digital Liquidity Fund is a tokenized money market fund that holds U.S. Treasury bills, cash, and repurchase agreements, all represented as on-chain tokens maintained at $1 per unit. Because BUIDL exists natively on blockchain, it can settle 24/7/365 without waiting for traditional market hours.
Ondo's CEO Nathan Allman explained the shift to CoinDesk at the time: OUSG would "become significantly more usable" with instant, around-the-clock subscriptions and redemptions. The migration happened in stages. Ondo moved $15 million initially, then minted another $79.3 million in BUIDL tokens on Ethereum within the same week. By the end of March 2024, Ondo held 38% of BUIDL's entire supply.
How the Plumbing Works
The relationship between OUSG and BUIDL operates through a specific fund structure that routes investor capital through institutional-grade custody.
When a user purchases OUSG, their stablecoins convert to USD through Coinbase, which serves as the primary banking partner. That USD enters the Ondo I LP fund structure, which then purchases shares of BUIDL. BlackRock manages the underlying portfolio, investing in short-term Treasuries and repos. BNY Mellon custodies the physical assets. The yield generated by these holdings flows back through the chain, increasing OUSG's net asset value over time.
According to RWA.xyz data, OUSG currently holds approximately $690 million in total assets, with the portfolio primarily allocated to BUIDL alongside smaller positions in Treasury funds from Franklin Templeton, WisdomTree, Fidelity, and Wellington Management. The diversification across multiple managers came later as Ondo scaled, but BUIDL remains the core holding.
The key advantage over BUIDL alone: accessibility. BUIDL requires a $5 million minimum investment and restricts access to qualified purchasers who pass Securitize's onboarding process. Ondo reduces that threshold to $5,000 for instant transactions, functioning as a retail distribution layer on top of BlackRock's institutional product. Investors who couldn't meet BUIDL's minimums can access substantially the same Treasury exposure through OUSG.
OUSG currently yields approximately 3.4% APY with a 0.15% management fee, and comes in two variants. The standard OUSG accumulates yield by increasing its token price (currently around $114 per token). The rebasing version, rOUSG, maintains a $1 price and distributes yield as additional tokens daily.
What BUIDL's Growth Means for Ondo
BUIDL's trajectory since launch illustrates the institutional appetite that Ondo benefits from. The fund grew from $40 million at debut to over $1 billion by March 2025, reaching approximately $2.9 billion at its mid-2025 peak. It has since settled around $1.7 billion after some redemptions, according to Messari. Circle's USYC briefly overtook BUIDL as the largest tokenized money market fund in January 2026, though BUIDL maintains a more diverse holder base with 103 distinct addresses compared to USYC's concentration in Binance wallets.
The multi-chain expansion matters for Ondo's growth plans. BUIDL now operates across seven blockchains: Ethereum, Solana, Polygon, Avalanche, Arbitrum, Optimism, and Aptos. Ondo confirmed its intention to diversify BUIDL reserves across these supported chains to facilitate liquidity in more ecosystems. OUSG is already available on Ethereum, Polygon, Solana, and the XRP Ledger, with additional chain deployments planned.
BUIDL's growing acceptance as collateral on trading platforms like Deribit and Crypto.com creates secondary demand that strengthens the asset backing Ondo's products. When more venues accept BUIDL as margin collateral, OUSG's utility as a yield-bearing position in DeFi protocols expands correspondingly. This collateral use case feeds directly into Ondo's Flux Finance lending protocol, where users can borrow against OUSG holdings. For a breakdown of how OUSG and USDY differ in structure and target audience, see our detailed comparison.
Beyond OUSG: The Broader BlackRock Connection
The BUIDL integration established credibility that extends beyond a single product. When Ondo launched Ondo Global Markets in September 2025, offering 200+ tokenized U.S. stocks and ETFs, the platform's association with BlackRock-grade infrastructure helped attract over $350 million in TVL within the first month.
The May 2025 cross-chain settlement test with J.P. Morgan's Kinexys unit used OUSG as the asset leg, demonstrating that BUIDL-backed tokens could settle atomically against traditional banking payments. For context on how that transaction worked across Chainlink's infrastructure, see the Ondo vs Chainlink RWA comparison.
Ondo Chain, the project's purpose-built Layer 1 blockchain for institutional RWAs, is designed to deepen these integrations further. The chain's architecture includes native support for compliance features and institutional custody, positioning it to eventually host BUIDL-backed products with even tighter settlement mechanics than existing multi-chain deployments allow.
For current technical analysis and price outlook, see the ONDO price prediction research.
The Distribution Layer for Institutional Yield
Ondo's relationship with BlackRock's BUIDL fund demonstrates a model that may define how tokenized finance scales: asset managers create institutional-grade products with high minimums and strict access requirements, while crypto-native platforms build distribution layers that extend access to smaller investors and DeFi protocols. Ondo functions as BlackRock's retail packaging layer, converting institutional Treasury exposure into formats that work across decentralized finance.
The risk profile tracks accordingly. OUSG's safety depends on BUIDL's management quality, BNY Mellon's custody, and the creditworthiness of U.S. Treasury securities. The additional layer of Ondo's smart contracts and fund structure introduces operational complexity that doesn't exist when holding BUIDL directly, but the tradeoff delivers accessibility and DeFi composability that institutional products alone cannot provide.
Trade ONDO on LeveX spot markets or through ONDO perpetual futures to position around RWA adoption catalysts. Explore our Crypto in a Minute series for deeper coverage of tokenized asset platforms and DeFi infrastructure.