Robinhood ChainHow close.fun works
close.fun is a token launchpad on Robinhood Chain (chain id 4663) where every pool keeps real US market hours. A token lists on the NYSE or NASDAQ at launch, and from that moment it can only be traded while the market is open — 9:30 to 4:00 ET, Monday through Friday. Nights, weekends and holidays are enforced at the AMM level. No frontend games: the pool itself refuses to trade after the bell.
Launching a token
Launches are real and non-custodial: your wallet submits every transaction. Fill in the name, ticker, description, image and socials, pick a paired asset, and hit Launch — the site switches your wallet to Robinhood Chain and deploys the token on-chain with your metadata embedded in the contract. Supply is 1,000,000,000, fixed at launch. The launch fee is gas only.
Every token starts on a bonding curve at roughly $3,000 market cap. An optional developer buy executes inside the launch transaction itself, so nobody can front-run your own launch. When the curve reaches $35,000 market cap the token graduates: a Uniswap v4 pool is created with the MarketHoursHook attached, all remaining inventory and raised ETH are seeded as liquidity, and the LP position is locked forever. A 1.00% creator fee accrues on curve trades.
One more rule, because this is close.fun: launches are only accepted while the market is open. If the button says the market is closed, set an alarm for 9:30.
The hook
Uniswap v4 lets a pool attach a hook contract that runs before every swap. When a token launches on close.fun, its pool is initialized with our MarketHoursHook and tagged with its exchange (NYSE or NASDAQ). On every swap attempt, beforeSwap asks the calendar whether the market is open right now. If it isn't, the swap reverts. There is no admin pause button, no multisig — the clock is the law.
// simplified contract MarketHoursHook is BaseHook { ExchangeCalendar public immutable calendar; mapping(PoolId => ExchangeId) public listing; function beforeSwap(address, PoolKey calldata key, ...) external view override returns (bytes4) { ExchangeId ex = listing[key.toId()]; if (!calendar.isOpen(ex)) { revert MarketClosed(ex, calendar.nextOpen(ex)); } return BaseHook.beforeSwap.selector; } }
The calendar
The ExchangeCalendar contract stores the weekly session window — 9:30 to 4:00 Eastern, with DST rules — plus the NYSE holiday list. Regular sessions are pure math on block.timestamp — no oracle needed for nights and weekends. Holidays and half-days are pushed ahead of time by a keeper and are fully auditable on-chain. Yes: your token observes Thanksgiving.
Tokenized stock pairs
Pools can be quoted in USDG (Global Dollar, the stablecoin behind Robinhood's stack) or directly in a Robinhood tokenized stock — launch BAGS/rTSLA if you want. When you pair against a tokenized stock, the hook locks your pool to the underlying's venue hours automatically. The pool trades exactly when TSLA trades, and never when it can't.
Why nothing depegs
Tokenized stocks drift on 24/7 AMMs because price discovery continues all weekend while the underlying is frozen — arbitrageurs have nothing to arb against, so gaps build up and "depeg" headlines write themselves. On close.fun the pool is only tradable when the real market is quoting. Every on-chain tick has a live reference price and a live arb path. The depeg window doesn't get defended — it gets deleted.
Liquidity
Only swaps are session-gated. Adding and removing liquidity works 24/7 — the hook leaves beforeAddLiquidity and beforeRemoveLiquidity open, so LPs can manage positions on weekends and rebalance before the open. Swap fees concentrate into 32.5 trading hours a week, which makes LP yield per open-hour dramatically denser than a 24/7 pool.
The close meta
When every session ends at 4:00 sharp, the close itself becomes the event. Power hour is real. The Friday close is a cliffhanger that lasts all weekend. The Monday open is a scheduled gap that everyone gets to trade at the same instant — no overnight whales, no 3am liquidations, just one bell and a fair line. Every day has a beginning, a middle and an end, and the tape gets to breathe.