How Does a “Constant Sum Market Maker” (CSMM) Attempt to Minimize Slippage for Stablecoin Pairs?

A Constant Sum Market Maker (CSMM) uses the formula x + y = k, where the sum of the reserves remains constant. This model is ideal for assets that are expected to trade near a 1:1 ratio, such as stablecoins.

Because the curve is linear, it allows for large trades with minimal price impact (low slippage) as long as the reserves are relatively balanced. This is a significant improvement over the Constant Product model for highly correlated assets.

How Does a Stablecoin Pool’s Formula Differ from the Constant Product Formula?
What Is a ‘Hybrid’ AMM and How Does It Combine the Features of CPMM and CSMM?
What Are the Trade-Offs between a Constant Product Market Maker and a Constant Sum Market Maker (X+y=k)?
What Is the Difference between a Constant Product Market Maker and a Constant Sum Market Maker?
What Is a Common Alternative AMM Formula Used to Reduce Impermanent Loss for Stablecoin Pairs?
How Do “Block Trades” in Options Markets Minimize the Impact of Slippage?
How Would This Formula Change for a Liquidity Pool Governed by a Constant Mean or Constant Sum Formula?
How Is the Invariant Formula for a Multi-Asset Pool, like Balancer’s Value Function, Different from the Constant Product Formula?

Glossar