What is a bonding curve on Pump.fun?

A bonding curve is a pricing formula, held in a smart contract, that sets a token's price from how much of it has been bought so far.

One sentence. Everything else follows from it.

How it differs from an order book

On a normal exchange, price comes from people. Buyers post bids, sellers post asks, a trade happens when they meet. Nobody selling? Then you can't buy.

A bonding curve has no counterparty at all. There's a contract holding 800 million tokens or so, and a formula. Send SOL, the contract calculates a price from how much has already been bought, and sells you tokens. Send tokens back, it buys them at the formula price.

Four consequences land immediately:

• Every buy raises the price for the next buyer, with nobody selling
• Every sell lowers it, because the contract buys back and the formula walks backwards
• There's always a trade available, though the price might not be one you like
• The path is deterministic. Given how much has been bought, the price is known

Why new coins move so violently

Early on, the formula is steep in relative terms. A 2 SOL buy on a coin that's had 8 SOL through it moves the price by a large percentage, because there's very little bought supply to average against.

Then apply that percentage to the entire supply when a market cap gets displayed. That's why the headline number on a fresh mint swings so hard in both directions, and it's the single most misread figure on any launchpad. What market cap actually measures goes into it.

What curve progress means

That percentage on your coin shows how far the curve has filled toward its migration threshold. Net buying drives it, so it climbs on buys and falls on sells.

Two things follow that matter to a creator.

It's public, and everybody checks it. Buyers read curve progress before they read your description, and 4% that hasn't moved in 3 hours reads as a coin nobody wants.

Stalling gets interpreted as a verdict. Mechanically a flat number means only that nobody has bought. Psychologically it means the coin has been judged and found wanting, and those are very different things, but the second one is what actually happens inside the head of the person looking at your page.

What is specific to the Pump.fun curve

The mechanism above is general. Any launchpad can run a bonding curve, and several do.

What Pump.fun fixes is every parameter. Same supply on every coin, same share held on the curve, same threshold before migration. There's no custom emission schedule to read, no team allocation, no vesting, and no treasury the protocol knows about.

Which produces a property worth understanding. On Pump.fun the economics are identical for everybody, so they stop being a differentiator. Two coins launched 40 minutes apart have exactly the same structure, and the only thing separating them is who bought and whether anybody found it. Supply and tokenomics covers what that means for your dev buy.

It also collapses a buyer's due diligence into 1 question. On a normal token launch they'd have to work out the float, when the first 25% unlocks and whether a treasury can sell. Here they open the holder list and they're done in 30 seconds.

What happens at the end

When the curve fills to its threshold, the coin graduates. Collected SOL seeds a pool on an automated market maker, and trading moves there.

After that:

• Price comes from pool reserves rather than a formula
• Slippage behaves differently, and large trades move price by different logic
• Routing and aggregation tools that read AMM pools can finally see the coin
• The curve contract is no longer the venue

What doesn't change is whether anyone wants the coin. Graduation is a liquidity event, not a demand event, and plenty of graduated coins go quiet immediately. The bonding curve guide has the full mechanics.

Why use bonding curves at all

They solve one specific problem. A brand new token has no market, and building one the traditional way needs somebody to provide liquidity and somebody else to take the other side of every trade.

Curves remove that requirement entirely. From second 1 your token is tradeable, priced, and impossible to launch without liquidity. What's the trade-off? Price early on is extremely sensitive, which is a feature for a launchpad and a hazard for whoever buys first.

The creator's summary

• The curve is a formula, not a market. Price comes from arithmetic, not opinion
• Small buys move a fresh coin a lot, and small sells move it back just as fast
• Curve progress decides graduation. Market cap decides how people feel
• A stalled curve usually means nobody saw the coin, not that people saw it and passed

That last point is the subject of why launches stall, and it's the distinction most creators get backwards.

If your curve hasn't moved since launch and you want to understand what to do about it, the console prices sustained activity against a specific window and wallet count before anything is signed.