How it works
One coin, created on pump.fun and on PONS in the same second, with a market maker funded by the coin itself. This page is the whole mechanism, including how the peg is held and what it costs.
Two native launches
A coin is created on pump.fun (Solana) and on PONS (Robinhood Chain) at the same opening market cap, with the first buy inside the creation transaction on both chains. Nothing can be in front of that buy: there is no moment between the coin existing and the seed being in it. Both launches land within about a second of each other.
The seed is paid in SOL by whoever launches the coin, plus a cash float of a quarter of each seed so the maker can buy the lagging side from its first minute. The pump.fun half stays in SOL; the PONS half is converted to ETH for you at launch. Together they become the coin's own market maker on both chains. duo.fun keeps a 0.5 SOL launch fee and never puts its own money into any coin's maker.
The maker is the coin's own
Each coin has two wallets, one per chain, that hold its seed. They start with the coin's tokens and a little cash. The maker watches both prices every few hundred milliseconds and acts on one rule: it sells the side that has run ahead and buys the side that lags, only when the gap between the two market caps is wider than what closing it costs.
Creator fees are not counted as a cost because they come back to the coin. On the bonding curves that rule works out to roughly 3.5% before the trade's own impact and 4 to 5% in practice; after graduation the venue fees fall and the band tightens. Two more gates: a side has to have moved at least 1% against its own recent average for the gap to count as real, and the buy leg is capped at 80% of what someone would have to spend to fake that gap, so pushing one price to farm the maker costs more than it can pay.
Cash stays on its own chain. When one side runs out of cash the maker only sells on that side until claims or sells refill it; it never borrows from the other chain and never asks duo.fun for money. If both sides are dry it holds and waits.
The band is what it is
The peg is not a fixed number, and that is deliberate: a fixed number is a promise that has to be paid for by someone, and on Twine that someone was the platform, until it could not. Here every coin page shows the band the maker can hold at that moment, given its cash and the current fees and depth, next to the live gap between the two caps. While the coin is healthy the two prices sit within a few percent of each other and every rebalance that keeps them there is listed with its transactions. When a side is out of cash the page says so, and the band widens until fees refill it.
Fees, split in the open
Every trade pays a creator fee: 2% on the Robinhood side, 0.3% to 0.95% on the pump.fun side depending on market cap. Those fees accrue to the coin's own wallets and are claimed regularly. Each claim is split the same way, and the split is on the coin page with its transaction:
| Order | Who | How much |
|---|---|---|
| 1 | duo.fun | half of the claim |
| 2 | the maker's reserve | from the other half, only until the maker holds a small cash cushion |
| 3 | whoever funded the coin | everything left: the dev on a solo launch, the backers pro-rata on a pool |
Payouts go out on every claim: SOL to the Solana wallet you gave, and the Robinhood-side share either to a Robinhood Chain wallet you gave or, if you gave none, as SOL at the day's rate.
Pooled launches
A coin can be launched as a pool instead of by one dev. Anyone sends SOL to the pool's address or chips in from its page; every transfer is credited to the wallet it came from. When the pool reaches its target the coin launches exactly like a solo one, and the backers get the coin's half of every claim pro-rata to what they sent, paid to the wallet they sent from. The list of backers and their shares is on the pool page and then on the coin page. A pool that has not filled in 72 hours refunds everyone automatically, minus network fees. Do not send from an exchange: shares and refunds go to the sending wallet.
Nothing gets delisted
A coin with no trade on either chain for a full day is retired: the maker sells what it holds back into both curves, everything left goes back to whoever funded the coin on both sides (the Robinhood side to their Robinhood wallet, or as SOL), and the coin's page stays up with its numbers. A dev can also retire early. Retired coins are never removed from the site.
$DUO
The platform's own coin, launched the same way as every other. A fifth of what duo.fun earns buys $DUO on the open market and hands it to the $DUO market maker as inventory, in public, listed on the site as it happens. Nothing is burned: the maker needs tokens to hold the two prices together, and that is where the buybacks go. This is not a dividend and not a yield; it is what the platform does with part of its take.
Stock pairs
A coin can also be quoted in a tokenised stock instead of SOL and ETH: the same stock on both chains, NVDA, TSLA, SPY and others. The seed is still paid in SOL and swapped into the stock for you; the maker then holds the stock and compares the two caps in it, so there is no exchange-rate risk between the sides. Fees arrive in the stock and are paid out as SOL and ETH. Stock pairs appear on the launch form once they are switched on.
What can go wrong
- The band widens. A one-sided run drains one side's cash; the maker then only sells there and the gap can stay open until claims refill it. The page shows this honestly.
- A coin dies. Most meme coins do. It retires after a day without trades and the seed left in the maker comes back to whoever funded it, minus what the maker spent holding the band.
- Prices move between paying and launching. If SOL falls in that window the Robinhood side opens slightly lower; if it rises the difference stays with the platform.
- Sending from an exchange. Fee shares and refunds go to the wallet that sent the SOL. An exchange's wallet is not yours.
- The peg is a mechanism, not a promise. Every coin's maker holds the two prices together whenever closing the gap earns more than it costs, with its cash, inventory and every trade on show. Twine promised a flat 5% and bled money defending it; we show the band the maker can actually hold, which is tight while the coin is healthy and wider when one side has run dry. A wider band is the maker protecting the coin's own money, and it tightens again as fees refill the cash.
duo.fun is the only official domain. Anyone can create a coin called anything on pump.fun or PONS; only coins linked from this site were launched here.