Spark, Uniswap, and Sky are launching a joint "Stablecoin FX Layer," shared programmable liquidity infrastructure for a multi-issuer stablecoin economy. The first deployment is a migration of roughly $150 million in USDS liquidity into Uniswap v4 pools, which the protocols describe as one of the largest AMM liquidity migrations in DeFi.
The three protocols announced the initiative Thursday in a joint post on Paragraph published by Spark. The migration targets two pools: USDS/USDT and USDS/PYUSD, both on Uniswap v4. Spark acts as the coordination layer, governing allocation frameworks and risk parameters; Sky's USDS, which carries a circulating supply of roughly $10.3 billion, provides the initial liquidity foundation.
Fragmented Liquidity
Stablecoins processed more than $28 trillion in economic volume in 2025, according to Chainalysis data cited in the Spark post. As the issuer count grows, including PayPal's PYUSD, Ripple's RLUSD, Revolut's planned stablecoin, Deel's DLUSD, Robinhood's reported ambitions, a euro stablecoin project from ING, BBVA, and BNP Paribas, and MUFG, Mizuho, and SMBC in Japan, each new issuer creates an isolated liquidity pool.
Capital is not scarce, the Spark post argues. It is fragmented across isolated pools where it cannot be deployed efficiently. Every issuer bootstraps liquidity independently, multiplying the coordination problem with each new token.
DualPool Hook
The technical mechanism rests on Uniswap v4's hook architecture. Uniswap v4 has processed $4.4 trillion in cumulative trading volume since launch and introduced hooks: modular smart-contract extensions that attach custom logic to pool events such as swaps and liquidity additions. The specific instrument here is the DualPool hook, which embeds programmable behavior directly into pool mechanics.
Spark governs the allocation framework on top. When liquidity in a given pool is not needed for trade execution, Spark can redeploy it across approved products within the Sky ecosystem, keeping idle capital productive rather than sitting dormant. The protocols describe this as solving the liquidity-versus-productivity tradeoff: capital earns yield while remaining available for settlement.
Sky's Role and the First Pools
Sky operates the USDS stablecoin alongside the legacy DAI, which carries a market cap of roughly $4.65 billion. Sky's total value locked stands at $5.76 billion per DefiLlama, with Spark holding an additional $4.6 billion in TVL as the capital-allocation arm that borrows from Sky's stablecoin reserves.
The $150 million migration deploys USDS into two pools: USDS/USDT and USDS/PYUSD. The PYUSD pairing means PayPal's stablecoin connects to the shared infrastructure directly, rather than bootstrapping an independent pool. The long-term vision is for issuers including Robinhood, Revolut, and bank-issued tokens to join the same layer, with USDS as the shared quoting asset.
Fidelity's dollar stablecoin routes liquidity through Uniswap, an earlier example of institutional stablecoin issuers choosing shared exchange infrastructure rather than building their own.
Yield-Bearing Liquidity
Under the current AMM model, liquidity providers commit capital to pools and forego returns while waiting for trades to clear. The DualPool mechanism routes uncommitted liquidity into the Sky ecosystem, through sUSDS and other Sky-approved products, until it is called on for execution.
J.P. Morgan projects global cross-border payment flows will grow from $194.6 trillion in 2025 to more than $320 trillion by 2032, the scale context the Spark post uses to frame the capital-efficiency argument for institutional issuers.
What Comes Next
The $150 million USDS migration is framed as a first step. Spark has previously published a risk framework for its Sky Agent Network, and the FX Layer announcement extends that infrastructure logic to multi-issuer liquidity coordination. Sky's $6 billion sUSDS yield pool provides the underlying product layer into which idle pool capital would flow.