Spark and Uniswap launched the first phase of a shared stablecoin liquidity layer on June 25, with about $150 million moved to Uniswap v4 on Ethereum.
The initial deployment uses two pools that pair Sky’s USDS with Tether’s USDT and PayPal’s PYUSD. Uniswap said the migration had been completed, while independent reports described the project as an attempt to create common foreign-exchange infrastructure for a market with a growing number of dollar-linked tokens.
For payment companies and stablecoin issuers, the important point is not another token launch. It is the effort to consolidate conversion liquidity across issuers so that each stablecoin does not have to rely entirely on isolated pools, separate market makers and capital fragmented across trading venues.
Two pools form the first phase
The live first phase uses standard Uniswap v4 pools, with USDS serving as the base asset against USDT and PYUSD. Crypto Briefing reported that Spark will act as the coordination layer and Uniswap v4 will provide the automated-market-maker infrastructure.
The companies describe the project as an “FX Layer,” but that label should not be confused with bank foreign exchange or guaranteed one-for-one conversion. The pools remain onchain markets whose execution depends on available liquidity, pool design and smart-contract operation. Issuer credit, redemption terms and chain risk remain specific to each stablecoin.
The roughly $150 million figure is a liquidity deployment, not payment volume, revenue or reserves held for all three tokens. It indicates the starting capital assigned to the trading infrastructure and should not be read as evidence of merchant adoption.
Shared liquidity targets a fragmentation problem
Stablecoin payment flows often need conversion even when both sides of a transaction are denominated in dollars. A wallet may hold one token while a merchant, exchange or settlement partner accepts another. Without deep common liquidity, that conversion can add price impact, routing complexity and inventory requirements.
A shared pool architecture can reduce some of that duplication by concentrating trading activity. It can also give payment orchestration providers a more consistent venue for routing between supported stablecoins. The commercial benefit will depend on real depth during stressed markets, transaction costs, security and whether additional issuers participate.
The design also introduces concentration questions. If more conversion activity moves through a small number of contracts or coordinators, failures in those components can affect several stablecoin routes at once. Payment firms integrating the layer will still need controls for slippage, token eligibility, smart-contract exposure and fallback routing.
DualPool and yield routing remain future work
Uniswap said the migrated liquidity is expected to move later to Spark’s new DualPool hook. The planned design would seek to put capital not immediately required for swaps into approved lending products, other liquidity venues or yield strategies while preserving active trading capacity.
That later phase was not live at the announcement. Crypto Briefing reported that the hook and shared-liquidity layer are due to undergo separate security reviews and testing before deployment. The distinction matters because capital efficiency can introduce additional dependencies and risk paths that are not present in standard pools.
The June 25 launch therefore establishes a funded starting point rather than a finished universal exchange layer. Its relevance to payments will be tested by execution quality, resilience and the ability to add regulated stablecoins without weakening risk controls or fragmenting liquidity again.