USDi is a native stablecoin on the Sui blockchain designed to maintain a 1:1 peg with the U.S. dollar. It is structured as a real-world asset (RWA) backed stablecoin, fully collateralized by shares in BlackRock's USD Institutional Digital Liquidity Fund (BUIDL). The project was announced in October 2025 as a collaboration between SUI Group (SUIG), the Sui Foundation, and Ethena Labs, with a projected launch by the end of that year. ^{[1] [2] [3]}​

Overview

USDi was developed as one of the first native stablecoins for the Sui Layer 1 blockchain, intended to enhance on-chain liquidity, utility, and financial infrastructure. It is positioned as a conservative, non-yield-bearing stablecoin focused on capital preservation and stability. This contrasts with its simultaneously announced counterpart, suiUSDe, a yield-bearing synthetic dollar developed with a different risk profile. The primary goal of introducing USDi was to create a stable, institutionally-backed store of value native to the Sui ecosystem, thereby reducing the network's reliance on third-party stablecoins like Circle's USDC and Tether's USDT. ^{[1] [2] [3]}​

The initiative was the result of a three-way partnership between SUI Group (SUIG), a publicly traded digital asset treasury firm; the Sui Foundation, the organization supporting the Sui network's growth; and Ethena Labs, a protocol specializing in synthetic dollar creation. While Ethena's mechanism is more directly applied to the suiUSDe project, it was a key partner in the broader stablecoin initiative. The stability of USDi is anchored in its 1:1 collateralization with shares of BlackRock's BUIDL fund, a tokenized money market fund that invests in short-term U.S. Treasuries and cash-equivalent assets. This backing by a real-world asset managed by a major global asset manager was intended to provide institutional-grade credibility and market confidence. ^{[1] [3]}​

History and Development

The creation of USDi occurred within a broader industry trend where Layer 1 blockchain ecosystems began developing their own native stablecoins to foster self-sufficiency and capture value. Projects on other networks, such as USDH on Hyperliquid and efforts by MegaETH, highlighted this strategic shift away from depending on external issuers. For the Sui network, this move was supported by its demonstrated capacity for high-volume transactions; in August 2025, the blockchain reportedly processed $229 billion in stablecoin transfer volume, indicating its technical readiness for a native stable asset. ^{[1] [3]}​

The formal plan to launch USDi and suiUSDe was announced on October 1, 2025, first reported by The Information and subsequently covered by other financial and crypto-focused media. The announcement detailed the partnership between SUI Group, the Sui Foundation, and Ethena Labs. The projected timeline set the launch for both stablecoins on the Sui mainnet before the end of 2025. ^{[1] [2]}​

Backing and Stability Mechanism

The design of USDi is centered on a fully collateralized model using a tokenized real-world asset to ensure its stability and peg to the U.S. dollar.

Collateral: BlackRock BUIDL Fund

USDi is fully backed 1:1 by shares of the BlackRock USD Institutional Digital Liquidity Fund, known by its ticker BUIDL. The BUIDL fund itself is a tokenized money market fund that invests its portfolio in secure, liquid assets, including cash, U.S. Treasury bills, and repurchase agreements. By collateralizing USDi with BUIDL shares, each USDi token is intended to represent a direct claim on a corresponding share in this regulated, professionally managed fund. This structure links the value of USDi directly to an on-chain representation of traditional, low-risk financial instruments, aiming to provide a high degree of stability and transparency. ^{[1] [3]}​

Tokenization and Issuance

The process of bringing the value of the BUIDL fund on-chain to back USDi involves multiple entities. The BUIDL fund's shares are first tokenized on the Ethereum network by the digital asset securities firm Securitize, which partners with BlackRock for this purpose. Subsequently, the issuance of the USDi stablecoin on the Sui blockchain is managed through the partnership between Sui Group Holdings and Ethena Labs. This multi-step process bridges traditional financial assets with the native environment of the Sui blockchain. ^{[1] [2]}​

Peg Stability

The 1:1 peg of USDi to the U.S. dollar is derived directly from its backing mechanism. Since each USDi is fully collateralized by a BUIDL token, which in turn represents a share in a fund holding dollar-denominated assets, the stablecoin's value is anchored to its underlying collateral. The stability of the peg relies on the on-chain minting and redemption mechanisms functioning correctly, allowing users to create and redeem USDi for its underlying BUIDL shares, thus ensuring the market price remains aligned with its intrinsic value. ^[3]​

Role in the Sui Ecosystem

The introduction of USDi was a strategic initiative aimed at fortifying the financial infrastructure of the Sui network.

Strategic Goals

A primary objective for creating USDi was to establish a native, reliable stablecoin to reduce the ecosystem's dependence on assets bridged from other blockchains, such as USDC and USDT. By creating a native asset, the Sui ecosystem can better retain and internalize liquidity and value flow, which might otherwise exit the network. USDi was intended to serve as a foundational building block for the increasing number of Decentralized Finance (DeFi) protocols on Sui, providing a stable asset for trading, lending, payments, and other on-chain activities. ^{[1] [3]}​

Dual-Stablecoin Offering

USDi was launched as part of a dual-stablecoin strategy, giving users a clear choice based on their risk tolerance and financial goals.

• USDi: The conservative, non-yield-bearing option designed for stability and capital preservation. Its backing by a BlackRock fund is aimed at risk-averse users and institutions.
• suiUSDe: The yield-generating counterpart, designed as a synthetic dollar for users seeking returns and willing to accept the associated risks of its underlying mechanism.

This dual offering allows the Sui ecosystem to cater to different segments of the DeFi market simultaneously. ^{[2] [3]}​

Key Parties and Partnerships

The development and launch of USDi involved a collaboration between several key entities in both the traditional and decentralized finance sectors.

SUI Group Holdings (SUIG)

​SUI Group Holdings, a Nasdaq-listed company, acted as the primary entity launching and issuing USDi. Formerly a short-term lender named Mill City Ventures, the company pivoted to a digital asset treasury model after a 300 million in SUI tokens as of September 2025 and having an agreement to acquire SUI tokens from the Sui Foundation at a discounted rate. The launch of USDi and suiUSDe was a core part of its strategy to become a publicly-traded entity focused on the stablecoin economy. ^[2]​

Ethena Labs

​Ethena Labs, a startup focused on stablecoin development, partnered with SUI Group to issue both USDi and suiUSDe. While its expertise in synthetic dollars was more directly leveraged for suiUSDe, it was an integral partner in the overall technical and strategic execution of the two-token initiative on Sui. Guy Young, CEO of Ethena Labs, commented on the choice of network, stating, "Sui’s performance and composability made it a clear choice." ^{[1] [2]}​

Sui Foundation

The Sui Foundation, the non-profit organization dedicated to the stewardship and growth of the Sui blockchain, was a key collaborator. Its support was crucial for integrating USDi as core infrastructure and ensuring its adoption within the broader ecosystem. ^{[1] [3]}​

BlackRock and Securitize

While not direct partners in the issuance of USDi on Sui, BlackRock and Securitize are foundational to its backing mechanism. BlackRock, a global asset manager, provides the BUIDL fund that serves as the underlying collateral. Securitize, a tokenization platform, is responsible for creating the digital BUIDL tokens on the Ethereum blockchain, making the fund's value accessible to crypto protocols like USDi. ^[1]​

Related Stablecoin: suiUSDe

Announced and launched in tandem with USDi, suiUSDe is a native stablecoin for Sui with a distinct mechanism and purpose. It is a yield-bearing synthetic dollar that mirrors the design of Ethena's USDe token. Its backing is derived from a combination of staked digital assets and corresponding short derivative positions, a strategy designed to generate yield for its holders. Developed in direct partnership with Ethena Labs, suiUSDe was created to serve as the higher-risk, higher-reward stable asset option within the Sui ecosystem, complementing the stability-focused USDi. ^{[1] [2]}