Uniswap Labs launched StablePair Hook on September 10, introducing a dynamic-fee hook (code that adjusts swap charges) for stable pairs on Uniswap v4. It went live on Ethereum mainnet with USDC/USDG and USDC/USDT pools. The launch targets a major decentralized finance market: stablecoin-to-stablecoin swaps reached $43.4 billion in the second quarter, more than the next three onchain venues combined, according to the company’s announcement. StablePair Hook is Uniswap Labs’ first upgradeable dynamic-fee design. It measures a pool’s distance from a reference rate and changes the fee on every swap, using a fixed bid-ask spread within a tight range and a Dutch auction (a fee that declines over time) for trades correcting larger deviations. The hook’s pool parameters and fee logic can be upgraded through Uniswap Governance without requiring liquidity providers to migrate. It joins DualPool, Permissioned Pools and LitePSM as the newest Uniswap Labs hook, while more are on the roadmap. Liquidity providers can port positions into the new pools, and traders can access them through the Uniswap Web App and Wallet. The release follows Uniswap’s crossing of $1 trillion in Layer-2 volume and reflects a focus on fee design, rather than token incentives alone, in attracting stablecoin liquidity. A separate Uniswap hook has already topped $500 million in usage.