A bonding curve is a mathematical pricing rule that links a token’s price to its circulating supply. In crypto, this rule is often implemented in a smart contract that automatically sets the buy and sell price as tokens are minted into circulation or burned out of it.
How bonding curves work on-chain
In a typical bonding curve contract, users purchase tokens by depositing a reserve asset, such as ETH, a stablecoin, or another base token, into the contract. The contract mints new tokens and charges a price determined by the curve at the new supply level. When users sell back, the contract burns tokens and returns reserve assets based on the curve’s sell price, with the exact mechanics depending on the design.
The curve can take many shapes. A linear curve increases price at a steady rate as supply grows, while steeper curves can make later tokens significantly more expensive. Some models reference reserve balance instead of supply, which can help maintain a predictable relationship between the token’s market capitalization and the collateral held by the contract.
Common uses and practical examples
Bonding curves are used to automate token distribution, fundraising, and market making. For example, a project could launch a community token where early participants buy at lower prices and later buyers pay more as demand and supply increase, without relying on a traditional order book. Bonding curve mechanics also appear in automated liquidity designs and have been used in systems inspired by continuous token models, where the contract itself is the counterparty for trades.
Bonding curves matter because they encode transparent, rules-based price discovery and liquidity directly into smart contracts, shaping incentives for early adopters, creators, and communities in the broader crypto ecosystem.