Real stocks,
fair swaps.

Swap tokenized shares for USDG on Robinhood Chain at the guarded Chainlink price, not at whatever a thin pool happens to say. The spread and the fee each get their own line, and every fill lands on-chain where anyone can read it.

01 · The formula

One equation. Nothing hidden behind it.

Every Zirplus quote is the same arithmetic run on public state. Take any fill on the explorer and you can rebuild its price from on-chain inputs.

  1. 176.40USDG

    Mid

    The Chainlink price, checked for staleness, wild jumps and corporate actions. If any check fails the market stops quoting instead of guessing.

  2. 10 bps× 1.0

    +Spread

    Each tier has a base half-spread (Tier A is 10 bps). The session multiplies it: ×1.0 while US markets are open, ×1.5 in extended hours, ×3.0 when closed.

  3. 0 bpsup to ±15

    ±Skew

    When a vault drifts from its 50/50 inventory, the side that brings it back gets a slightly better price. Rebalancing pays for itself.

  4. 2 bpsown line

    +Fee

    Shown on its own line on the ticket and recorded in its own field of the fill event. Never folded into the price curve.

= your price, NVDAx example

176.61USDG

That is 12.0 bps over the mid, all costs included. And there is a hard wall: whatever the parameters say, no fill from a vault or a maker can settle more than 75 bps from the mid in Tier A.

-75mid+75
  • Recomputed on-chain

    Inside your transaction the router rebuilds the vault quote from oracle and vault state. A front end cannot route you to anything worse than the formula.

  • Makers must beat it

    A signed quote from an attested market maker only settles if it pays you more than the vault would. Otherwise the vault fills you.

  • Worse means revert

    You sign a minimum output and a deadline. If the price moves past either before your transaction lands, it reverts instead of filling.

02 · Market hours

The chain never sleeps. The stock market does.

Stock Tokens move on-chain around the clock, but the exchanges that set their price are open for about 32 hours a week. Zirplus reads the session from the oracle and prices each hour honestly.

00:0003:0006:0009:0012:0015:0018:0021:0024:00
OpenExtendedClosed

Open

14:30 – 21:00 UTC, weekdays

Spread
×1.0
Max swap
×1.00

US exchanges are trading, so the vault quotes at the tier's base spread with its full clip size.

Extended

09:00 – 14:30 and 21:00 – 01:00

Spread
×1.5
Max swap
×0.75

Pre and post market. The underlying is thin, so spreads widen and the biggest single swap shrinks.

Closed

Overnight and all weekend

Spread
×3.0
Max swap
×0.50

No exchange is open to anchor the price. Quotes keep coming, priced for the gap risk until the next open.

Weekends are priced, not banned

Saturday and Sunday count as closed from start to finish. You can still swap, at ×3 the spread and half the clip, and the ticket tells you so before you sign. Refusing to quote would bring office hours to a chain that runs 24/7; quoting weekday spreads on a Saturday would quietly hand the gap risk to LPs. Neither is fair.

Tier A today: 10 bps base, so 30 bps when closed.

When quoting stops entirely

  • The feed is older than the staleness limit for the current session
  • The issuer flags a corporate action and the feed reports itself paused
  • A single print jumps more than 25% against the recent checkpoint
  • The chain's sequencer goes down, plus a recovery grace period after it returns

A halt only stops new prices. LP withdrawals never depend on the oracle, so they keep working.

03 · Routing

Two venues, one door

Everyday orders fill instantly against vaults anchored to the oracle. Big orders are put out to professional makers as signed quotes. A single router prices both and settles whichever pays you more.

Anchorvaultsstandard sizeRFQmakersblock sizeRouterbest wins
Vault lane
Two-sided quotes around the guarded mid in every market. Tier, session and inventory set the spread; you can work the price out yourself.
RFQ lane
Orders big enough to move a curve go to attested makers instead. Their signed quote settles atomically against their own wallet, and only if it beats the vault.
The router
Checks eligibility and the oracle band, prices both lanes and settles the better one. A stock-to-stock swap runs as two legs through USDG in one transaction; if either leg fails, both revert.

75 bps

the hard band around the mid in Tier A

2 bps + 10%

swap fee, plus the protocol's share of spread

0

assets held by the venue between trades

  • Traders

    Swap at any hour at an itemised price. The ticket shows which session you are in before you sign.

  • Liquidity providers

    Fund a vault and earn the spread it collects. Withdrawals are in kind and work in every state, even halted or paused.

  • Market makers

    Answer block-size requests with signed quotes. Quoting is free; you only fill when you beat the vault.

04 · Why not a normal pool

Shares are not memecoins. Stop pricing them like one.

Constant-product pools are great for crypto pairs. For an asset whose real price is set on an exchange, they drift, overcharge and leave LPs exposed. Here is the difference, line by line.

  • Where the price comes from

    Generic pool

    Whatever is sitting in the pool's reserves

    Zirplus

    The guarded Chainlink mid, held inside a hard band

  • A Saturday trade

    Generic pool

    Priced as if it were Tuesday afternoon

    Zirplus

    Wider spread and smaller size, shown before you sign

  • Liquidity providers

    Generic pool

    Picked off by arbitrage every time the stock moves

    Zirplus

    Earn the spread, and skew pays others to rebalance them

  • Stock splits and corporate actions

    Generic pool

    The pool breaks or has to migrate

    Zirplus

    The market pauses, then resumes on the adjusted feed

  • A large order

    Generic pool

    Walks down the curve and pays for it

    Zirplus

    Goes to competing makers as signed quotes

  • Fees

    Generic pool

    Blended into the curve

    Zirplus

    Listed on the ticket and logged in the fill event

We see the two as neighbours, not rivals. Arbitrageurs who pull generic pools towards the anchored price bring useful flow, and skew pricing pays them for rebalancing our vaults along the way.

05 · The chain

Built where the shares already live

Robinhood Chain is where Stock Tokens are issued, priced and held. Building the venue there removes bridges, wrappers and guesswork from the path between you and the asset.

Network
Robinhood Chain, built on Arbitrum Nitro and fully EVM-equivalent
Assets
Stock Tokens issued as ordinary ERC-20s
Prices
Chainlink feeds that also report market status
Settlement
USDG, native to the chain
Receipts
Every fill visible on Blockscout
Mainnet chain ID
4663
  • No allowlist in the way

    Stock Tokens are plain ERC-20s, so nothing stands between an eligible wallet and a swap.

  • The clock comes with the price

    The session flag that drives our regimes arrives from the same oracle that prices the fill.

  • Cheap enough for small trades

    Low fees make a $50 swap sensible and let quotes refresh constantly.

06 · Pledges

Eight things we promise, and how to check each one

Saying 'transparent' is free. These are commitments you can test yourself. If one ever fails its check, we treat it as an incident and publish what happened.

  1. 01

    Every fill is itemised

    Mid, spread, skew and fee are separate fields in the fill event, matching the ticket line for line.

    Check Open any fill on Blockscout and compare it with its ticket.

  2. 02

    Nothing settles outside the band

    The band is a contract check on both the vault path and RFQ, not a promise in a policy page.

    Check Run the fuzz and invariant tests in contracts/test.

  3. 03

    Best verifiable price wins

    The router compares the vault quote with any maker quote on-chain and settles the better one.

    Check Call previewExactIn with the same inputs and compare.

  4. 04

    No custody, anywhere

    Settlement is atomic, and vault inventory belongs to LPs. Between trades the venue holds nothing.

    Check Read SwapRouter: it has no owner and no sweep function.

  5. 05

    Exits are unconditional

    Withdrawals are pro-rata and in kind, and they work halted, paused, retired or with an expired attestation.

    Check See the withdrawal-in-every-state tests.

  6. 06

    Changes are timelocked

    After bootstrap, every parameter change is scheduled, waits out the delay and only then executes.

    Check Follow ParamController's schedule and execute events.

  7. 07

    The guardian can only pause swaps

    Deposits, withdrawals and RFQ cancellations sit outside anyone's pause button.

    Check Read ParamController: the guardian role can call one thing, the swap pause.

  8. 08

    Open source, no proxies

    The router, vaults, factory and RFQ settlement have no upgrade path. New versions are new deployments.

    Check Verify the bytecode against this repository.

07 · Questions

Straight answers

The short versions. For anything else, read the source or write to us.

Is Zirplus an exchange?

It is a swap venue that never takes custody. Anchored vaults and competing makers supply prices, settlement happens atomically on Robinhood Chain, and your assets stay in your wallet until the moment they swap. There is no order book and no account to fund.

Why is the spread wider tonight than this afternoon?

Because the stock market is closed. Liquidity providers carry the risk of a gap until the next open, so closed-session quotes use a ×3 spread multiplier and a smaller maximum size. The session badge on the ticket always shows the multiplier before you sign.

If I buy tokenized Apple, do I own Apple shares?

No. You hold a Stock Token, an ERC-20 issued against the share that tracks its price. It is a claim on the issuer, not a share registered in your name. Read the issuer's terms before you trade.

Where does LP income come from?

From the spread each vault earns on its fills, less the protocol's 10% share, paid into the value of your vault shares. There are no emissions and no points. Because quotes follow the oracle, arbitrage does not drain the vault the way it drains an AMM; the real risks are price exposure to your token, weekend gaps and issuer risk.

Who decides the price?

A formula over public state: the guarded mid, the tier spread times the session multiplier, the inventory skew and an itemised fee. Nobody at Zirplus can change a quote or a fill, and parameters only move through a timelock.

Do I need to be verified?

Yes, to trade, provide liquidity or make markets. A KYC provider issues a role attestation to your wallet; only the role, a jurisdiction class and an expiry go on-chain. You never need one to withdraw from a vault.

Can I build on Zirplus?

Yes. The router is a public contract with a stable interface, and eligibility belongs to your users' wallets rather than to any particular app. The official site gets no special route.

The price is the price.
Everything else is a line item.

Verified traders can swap within minutes. LPs earn the spread, makers quote for free, and every fill settles on Robinhood Chain.