How Does the ‘Constant Sum’ Formula Differ from the ‘Constant Product’ Formula in AMMs?

The Constant Product formula (x y=k) ensures that the product of the reserve quantities (x and y) remains constant, which results in a smooth but exponentially increasing price impact (slippage) for large trades. The Constant Sum formula (x+y=k) aims to keep the sum of the reserves constant, resulting in a linear, near-zero slippage price for trades.

This formula is primarily used for stablecoin pairs that should trade at a 1:1 ratio.

How Do Algorithmic Stablecoins Differ from Asset-Backed Stablecoins?
How Do “Stableswap” AMMs Modify the X Y=k Formula to Reduce Impermanent Loss for Stablecoins?
Explain the Difference between a Constant Product and a Constant Sum AMM Curve
How Would This Formula Change for a Liquidity Pool Governed by a Constant Mean or Constant Sum Formula?
How Do Hybrid AMM Models, like Curve’s StableSwap Invariant, Improve upon the Constant Product Formula for Stablecoin Trading?
What Is a ‘Wrapped’ Token and Why Is It Often Used in Token Pairs?
Name a Common Mathematical Formula Used by AMMs besides X Y = K
How Does a Constant Sum Market Maker (X+y=k) Differ from a Constant Product AMM?

Glossar