SynthStocks

SynthStocks is a multichain synthetic stock trading platform that brings compliant, permissionless access to tokenized equities.

The Problem
Today's tokenized stock platforms like Backed Finance and Ondo issue real-world asset tokens but have no on-chain mechanism to verify who is buying them. There's no allowlisting - anyone with a wallet can accumulate unlimited tokens, creating regulatory blind spots around concentration risk and sybil abuse. Existing compliance is either fully centralized (KYC gatekeepers) or entirely absent. Neither approach scales for global, 24/7 markets.

The Solution
SynthStocks solves this with three key primitives:

1. Human-only access via World ID - Every trader must prove they are a unique human through a zero-knowledge biometric check before they can trade. No personal data is shared, but sybil attacks are eliminated. One person, one verified identity, across all chains.
2. On-chain compliance via holding limits - The protocol enforces maximum holding percentages per token, preventing any single actor from accumulating an outsized position. Violations are automatically detected and flagged by decentralized compute - not a centralized admin.
3. Decentralized compute via Chainlink CRE - Real-time stock prices, cross-chain supply synchronization, verification propagation, and compliance monitoring all run through Chainlink's Compute Runtime Environment. No single server controls the data pipeline - price feeds, supply caps, and identity state are kept in sync across Base, Arbitrum, and Avalanche without centralized infrastructure.

How It Works
A user connects their wallet, verifies their humanity with World ID, and is instantly allowlisted on all supported chains. They can then buy synthetic stocks (sAAPL, sNVDA, sTSLA, sAMZN, sMETA, sGOOG) using USDC at live market prices. Every trade mints or burns tokens against a global supply cap enforced across chains, ensuring no over-issuance regardless of which network the trade happens on.

Architecture : https://github.com/user-attachments/assets/b69d5689-629f-4d45-8446-fc0ef5e1ee21

The Result
Compliant tokenized stock trading that is open to anyone, gated only by proof of personhood - not geography, not paperwork, not intermediaries.

SynthStocks runs on a MultiTokenExchange smart contract deployed identically across Base, Arbitrum, and Avalanche. Each chain holds the same synthetic stock tokens, a shared USDC liquidity pool, and per-token price feed contracts. All trading logic - minting, burning, verification gating, supply cap enforcement - lives on-chain.

Chainlink CRE Workflows
The cross-chain intelligence layer is powered by four Chainlink CRE workflows, each designed to react to on-chain events in real time:

• Price Feed - Pulls live stock prices from market data APIs every 30 seconds and writes them to each chain's price receiver contracts. Every buy and sell executes against a fresh, decentralized price - not a stale oracle.
• Supply Sync - Triggered by Buy and Sell events on any chain. When a trade happens on Arbitrum, CRE reads the token's total supply across all three chains, computes each chain's cross-chain supply, and writes it back. This ensures the global supply cap is enforced collectively - a user on Avalanche cannot over-mint just because Base hasn't synced yet.
• Verify Sync - When a user's World ID proof is verified on one chain, the UserVerified event triggers a CRE workflow that propagates that verification to every other chain automatically. This means a single proof of personhood on Base instantly allowlists the user on Arbitrum and Avalanche - unified identity across chains without bridges or message passing. Any new chain added to the protocol simply becomes another CRE target, and existing proofs flow to it automatically.
• Holding Monitor - Listens for token Transfer events and checks whether any recipient now exceeds the protocol's maximum holding percentage. If they do, CRE flags them on-chain - preventing further accumulation without requiring a centralized compliance team.

World ID Integration
World ID v4 generates a zero-knowledge proof of personhood on the user's device. The proof includes a nullifier hash - a unique, anonymous identifier that prevents the same human from verifying twice. The backend verifies this proof, then calls verifyOffchain on the exchange contract. CRE's verify-sync ensures this one-time proof reaches every chain in the network, turning a single biometric check into a multichain trading passport - no personal data stored, no KYC paperwork, no centralized allow list.