Robinhood Stock Prediction Market
A parimutuel stock prediction market built on Robinhood Chain Mainnet, using native Stock Tokens (TSLA, AMZN, PLTR, AMD, NVDA) and live Chainlink Data Feeds as the price oracle.
Live Demo · Network: Robinhood Chain Mainnet (Chain ID 4663)
What's New vs. Existing
Existing (pre-hackathon)
- Parimutuel prediction market contract — live on Robinhood Chain Mainnet
(Chain ID 4663) since July 3, 2026 (
b7b2071, d45fb8e). Real on-chain
history to date: 29 createMarket, 27 lockMarket, 27 settleMarket,
3 placeBet, 2 claimWinnings (independently counted, da13c80; second
claimWinnings on market 14 appeared on-chain 2026-09-08).
- React + wagmi frontend, deployed to Vercel (
f40f9a1, 0e2688d,
through subsequent fixes to 17c4ba9).
- VPS-based keeper for
lockMarket/settleMarket operation (664d535,
b4748f6, and other maint: commits).
- Independent settlement verification layer (
da13c80, added
September 3, 2026 ahead of Continuity Track submission): a Python
reference model derived from the contract's external spec/ABI, cross-checked
against all 27 real settleMarket transactions and both real
claimWinnings transactions pulled directly from chain. 29/29 match; trace
sealed via SHA-256 (verification/settlement/commitments.sha256).
Findings: no decimals-normalization in the price-read path (dormant to
date); README's claimed no-winner refund path has no implementation
(never triggered); all real settlements to date resolved via
tie-defaults-to-BULL rather than genuine price movement. A follow-up check
(1db88b1) found genesis-era rounds on all 5 price feeds report answers
scaled at 18 decimals instead of the 8 decimals() reports — 222
anomalous rounds total, non-uniform cutoffs per feed, confirmed one level
below the proxy via .aggregator(). To our knowledge this is undocumented
elsewhere. No real settlement has touched an anomalous round to date
(~9.9-day buffer). Full detail in
verification/settlement/comparison_report.md.
New (this hackathon — Continuity Track)
Core Features
Chain-Native Stock Token Integration
Each market is anchored to a Robinhood Chain native stock token address. createMarket() accepts address stockToken directly, creating an on-chain verifiable link between the prediction market and the actual tokenized equity — something only possible on a chain purpose-built for RWA.
Live Chainlink Data Feeds
The contract reads real-time stock prices via Chainlink AggregatorV3Interface. Each stock has a dedicated ChainlinkPriceFeed wrapper deployed on Robinhood Chain Mainnet, connected to Chainlink's official price feed proxies live from day one of mainnet launch.
Parimutuel Settlement
No order book, no counterparty risk. BULL and BEAR pools accumulate independently. At settlement, the winning side splits the total pool proportional to their stake, minus a 2% protocol fee.
Full Market Lifecycle
OPEN → LOCKED → SETTLED. lockMarket() snapshots the opening price from the oracle. settleMarket() reads the closing price and determines the winning direction.
Architecture
Source: docs/architecture-source.html (rendered via Puppeteer — see the comment at the top of
that file before editing either one).
*Fixed 2026-09-22 per ADR-12 (prompts/15-refund-tie-openprice-fix.md): openPrice is now
snapshotted inside createMarket(), at the moment the market is opened, so bettors always have
an on-chain reference price to bet against for the entire OPEN window. lockMarket() is now a
pure state transition — it no longer reads the price feed at all. If a Chainlink round hasn't
updated between open and settle and closePrice == openPrice, settleMarket() now puts the
market into a REFUND state instead of defaulting to a BULL win: every bettor on both sides
reclaims their exact original stake via claimWinnings(), with no fee deducted. settleMarket()
also falls back to the same REFUND state if the price-implied winning side's pool is empty
(nobody actually bet on the direction the price moved) — this closes a fund-lock gap an
independent security review found, where the losing side's entire pool would otherwise become
permanently unclaimable. This is tested behavior (test_12_tieSettlement_refundBothSides,
test_19_tieDirectionOnly_noBets_matchesTC09, test_22_refundState_bothSidesClaimFullPrincipal_skewedPools,
test_23_settleMarket_emptyWinningSideBull_refunds, test_24_settleMarket_emptyWinningSideBear_refunds
in test/StockPredictionMarketV2.t.sol). Both price reads (createMarket()'s openPrice,
settleMarket()'s closePrice) also now validate the oracle response itself — the price must
be positive, the round must be complete (answeredInRound >= roundId), and the update must be
no older than STALENESS_THRESHOLD (4 hours) — before it's trusted for any market logic.
The original StockPredictionMarketV2 deployment (0x59DF30E22bdaC70764a5DbF8bBa51BC5a595759C,
now deprecated) carried this limitation as documented, intentional-but-unfixed behavior — see
ADR-12 for the full before/after context.
Deployed Contracts
Robinhood Chain Mainnet (Chain ID: 4663)
| Contract | Address |
|---|
| StockPredictionMarketV2 (V3 fix) | 0x06897Ce6A2492BE99B59a7c023A64A6C0Af37849 — deployed 2026-09-22 per ADR-12 (prompts/15-refund-tie-openprice-fix.md), fixing the openPrice-snapshot-timing and default-BULL-tie bugs described below, plus three follow-up fixes from an independent security review (empty-winning-side REFUND, Chainlink oracle staleness/round/timestamp validation) |
| StockPredictionMarketV2 (original) | 0x59DF30E22bdaC70764a5DbF8bBa51BC5a595759C — deprecated 2026-09-22, superseded by the V3 fix above; no longer referenced by frontend, decision-engine, or any new code |
| StockPredictionMarket | 0x72DAb8B1B53b3CF028e9A0d1E21178981f264245 — deprecated, no longer referenced by frontend or any new code |
| AgentStockMarket | 0xE8b3916Ea16AD2F2C0910bB94005e30F5CC341D3 — deployed 2026-09-05, superseded one day later when ADR-10 merged its attestation-verification logic into StockPredictionMarketV2.placeAgentBet(); no longer referenced by any frontend, decision-engine, or relayer code |
| TSLA ChainlinkPriceFeed | 0x072A3A0C04Cf8CDcaf5B4A73a4Ed4fF5A841531f |
| AMZN ChainlinkPriceFeed | 0xcAC5B9d2817325E78090E3Ce4b9C299C819cF953 |
| PLTR ChainlinkPriceFeed | 0xBdC53E50b1167cE1199bFaD54A034f7ab1741051 |
| AMD ChainlinkPriceFeed | |
Chainlink Price Feed Proxies (Official, Robinhood Chain Mainnet)
Robinhood Chain Stock Tokens (Official)
Robinhood Chain Testnet (Chain ID: 46630) — Legacy
Quick Start
Prerequisites
- Node.js 18+
- A funded wallet on Robinhood Chain Mainnet
# 1. Install dependencies
npm install
# 2. Configure environment
cp .env.example .env
| Variable | Description |
|---|
PRIVATE_KEY | Deployer wallet private key (no 0x prefix) |
# 3. Compile
npx hardhat compile
# 4. Deploy to mainnet
npx hardhat run scripts/deploy.js --network robinhoodMainnet
Contract Interface
// Create a new prediction round
createMarket(address stockToken, address priceFeed, string symbol, uint256 duration) returns (uint256 marketId)
// Place a bet (send ETH as value)
placeBet(uint256 marketId, Direction direction) // Direction: 0 = BULL, 1 = BEAR
// Lock market and snapshot opening price
lockMarket(uint256 marketId)
// Settle market and determine winner
settleMarket(uint256 marketId)
// Claim winnings after settlement
claimWinnings(uint256 marketId)
Fees & Security
Fees
- Protocol fee: 2% of total pool at settlement
- No winner scenario: all bets refunded in full
Security
- One bet per address per market
- Minimum bet enforced (0.001 ETH)
- Owner-only market lifecycle controls (createMarket, lockMarket, settleMarket)
- No reentrancy risk: claimed flag set before transfer
- Chainlink staleness check: 3-day threshold (covers weekends and market holidays)
Implementation Notes
Live Chainlink Integration
Robinhood Chain launched mainnet on July 1, 2026 with Chainlink as the official oracle layer from block zero. This contract integrates Chainlink Data Feeds via a ChainlinkPriceFeed wrapper that implements IPriceFeed (mirrors AggregatorV3Interface). Replacing or upgrading feeds requires only a constructor argument change — zero contract modifications.
Stock Token as Market Identifier
On most chains, a prediction market would use an arbitrary string or uint to identify a market. On Robinhood Chain, we use the native stock token contract address directly, creating an on-chain verifiable link between the prediction market and the actual tokenized equity.
Honest Disclosure: AgentKit Relayer
The relayer/ service is a trusted-signer relayer bridge, not a trust-minimized one. It
verifies a World AgentKit-signed agent request, checks the agent's wallet against World Chain's
AgentBook for a registered humanId, enforces its own replay-nonce, and signs an attestation
with a relayer-held private key. StockPredictionMarketV2.placeAgentBet()
(contracts/StockPredictionMarketV2.sol) does verify and consume that attestation on-chain: it
ecrecovers the signature against relayerAddress, checks expiresAt and usedAttestations,
and credits the bet into the same bullPool/bearPool a human's placeBet() uses.
decision-engine/src/agent-tx.js builds, simulates, and can broadcast that transaction from the
agent's own wallet — the agent pays its own gas, the relayer never funds or broadcasts anything
— but its own code comment is explicit that the broadcast step is never invoked automatically
and is meant to be wired up only behind an explicit human confirmation. Nothing in this pipeline
runs unattended end-to-end today.
Separately: the agent wallet this project actually uses currently reads unbacked on AgentBook
(57/57 live reads against real, freshly generated addresses returned unbacked — see
prompts/08-world-id-orb-availability-constraint.md), because obtaining a real Orb-verified
World ID is blocked by an external constraint: Taiwan has no stably operating Orb location, and
a possible World ID Sandbox workaround was never confirmed compatible with AgentBook's on-chain
groupId=1 check. Concretely, this means the relayer currently refuses to sign an attestation
for this agent at all (agent_not_human_backed), so placeAgentBet() can never be reached with
a validly-signed attestation through the real pipeline as it stands — the backed branch's
correctness has been verified by code review and unit tests only (relayer/src/agent-book.js,
exercised in relayer/test/replay.test.js and decision-engine/test/), not by a live on-chain
bet.
Separately, and identified after the fact during design: World ID (and therefore AgentBook)
proves an agent maps to one distinct real human — uniqueness — not that the human authorized
this specific spend or amount, and not a post-hoc auditable record of that authorization. The
current design only blocks agent bets with no real human behind them at all; it does not yet
cover spend limits, scoped authorization, or accountability after the fact. See
prompts/03-calibrated-autonomy-boundary.md for the full reasoning.
The lookupHuman three-state read (backed / unbacked / unknown, so an AgentBook RPC
failure is never reported as "not registered") follows the pattern documented in
poh-aggregator's
lookupHumanBacking —
credited here as prior art this implementation deliberately follows, not independently arrived at.
Stack
| Layer | Technology |
|---|
| Smart contract | Solidity ^0.8.20 |
| Development | Hardhat 3 + ethers.js |
| Oracle | Chainlink Data Feeds (AggregatorV3Interface) |
| Stock tokens | Robinhood Chain native (TSLA, AMZN, PLTR, AMD, NVDA) |
| Frontend | React + wagmi v2 + Vite |
| Deployment | Vercel |
Roadmap
✅ M1 — Contract Deployment
- StockPredictionMarket deployed on Robinhood Chain Testnet
- Parimutuel logic with BULL/BEAR markets
- MockPriceFeed (Chainlink-compatible) per stock token
✅ M2 — Frontend
- React + wagmi frontend
- Live market odds display, bet placement, claim UI
- Deployed to Vercel
✅ M3 — Mainnet
- Deployed to Robinhood Chain Mainnet (Chain ID 4663) on July 3, 2026
- Replaced MockPriceFeed with live Chainlink Data Feeds
- TSLA / AMZN / PLTR / AMD / NVDA markets live
⬜ W3 — Keeper Automation
- VPS-based keeper for automatic lockMarket / settleMarket
- Scheduled via cron on Hetzner VPS
⬜ W4 — Architecture Diagram
⬜ W5 — NatSpec Documentation
Developer
GitHub: pplmaverick
Wallet: 0xed2B5717c9b936ecC76d75401026A99143e278F5
License
MIT
