What is a bonding curve? Meme coin pricing explained
5 min read · Updated September 27, 2026
A bonding curve is a price formula written into a smart contract. Instead of waiting for someone to put up liquidity, the contract itself sells the coin: every buy pushes the price up a little, every sell pushes it down. It is the engine behind almost every modern meme coin launchpad.
How the price moves
The most common design uses two virtual reserves, one of ETH and one of the coin, whose product stays constant. When you buy, ETH goes into the reserve and coins come out, so the next coin costs a little more. When you sell, the opposite happens. The formula is public and the same for everyone, so the price at any moment follows directly from how much has been bought and sold.
- Early buyers pay less per coin than later buyers.
- Big buys move the price more than small ones.
- The price you see is the price you get, minus the fee and any movement while your transaction lands.
Why you can always sell back
Because the curve holds all the ETH that buyers paid in, it can always pay out a seller according to the same formula. There is no order book that can run dry. On sasa this is guaranteed by the contract: until graduation, anyone can sell back at any time, and the curve always holds enough to buy every coin back.
What graduation means
A curve is a starting point, not a permanent home. Once a set amount of money has gone in, the coin graduates: the ETH in the curve and a matching amount of coins become a regular trading pool on a decentralised exchange, at the same price the curve reached. On sasa that pool is locked forever, so the liquidity can never be removed.
Fees
Every buy and sell on a curve pays a small fee. On sasa it is 1%: 0.3% goes to the coin's creator and 0.7% to the platform. The same split continues in the locked pool after graduation.
Bonding curves across several chains
On sasa a coin can launch on several chains at once, each with its own curve. Buys on every chain add up to one graduation target. When it is reached, the curve holding the most money graduates, the others stop taking buys, and holders there can still sell back whenever they like.
Questions
Is a bonding curve safe?
The formula itself is simple and transparent. What matters is the contract around it: a fixed supply, no owner who can take the funds, and a guaranteed sell-back until graduation. sasa's contracts are built that way and will be independently audited before mainnet.
Why does my buy get fewer coins than the quote said?
If others buy just before you, the price moves. sasa cancels a trade automatically if the price moves more than 5% while it is confirming, so you never pay more than you agreed to.
What happens to my coins at graduation?
Nothing changes for holders: your coins stay in your wallet and now trade in the locked pool instead of on the curve.