StarkWare OffMarket lets Polymarket traders hide positions

StarkWare has opened OffMarket to the public, a web app that lets Polymarket users trade the same markets without their positions being publicly linked to their accounts. StarkWare OffMarket runs on a privacy layer built on Starknet and had been in limited release since August. Deposits are capped at $1,000 in USDC for now, The Block reported.

What happened

According to the OffMarket site, deposited USDC goes into a smart contract on Starknet, where zero-knowledge proofs encode balances and activity so that only the user's viewing key can read them. For each bet the app derives a fresh Polygon wallet that places the order on Polymarket, and funds move between chains through Circle's CCTP bridge. Users trade the same order book at the same odds.

The site says the Starknet contract is public and immutable and that no administrator can access user funds. When users return funds, the bridge process runs in reverse, and OffMarket says the transfer carries no identifying information.

Crypto Briefing said the rollout started with a private alpha in July, followed by invite-only access in August and mainnet privacy trading in September, with public availability around Oct. 14. The project carries Official Polymarket Builder status but operates independently of Polymarket.

The Block said the Starknet privacy pool holds about $1.5 million from roughly 17,000 deposits, citing L2BEAT. OpenZeppelin audited the system in June, and U.S. users are barred from the app.

Users can sign in with Google or connect a crypto wallet, deposit USDC and trade without creating a Polymarket account, according to the OffMarket site and Crypto Briefing. StarkWare compares it to a VPN for Polymarket, with the same markets but less visibility into who is betting.

Why it matters

On Polymarket, every account, trade history and portfolio is public, so large traders can be tracked, copied or front-run. StarkWare OffMarket aims to give them some cover while keeping them inside Polymarket's liquidity rather than a thinner side venue.

Privacy cuts both ways in this market. Bloomberg flagged some 34,000 potentially suspicious trades on Polymarket between August 2025 and June 2026, The Block noted, and lawmakers are already pressing platforms on insider trading. Tools that break the public link between wallets and bets could make that kind of outside scrutiny harder.

There are limits. The Block said OffMarket cannot stop observers from identifying trades by size or timing, and the builder code that tags its orders can be disabled. Polymarket volume also gives context, at $13 billion in September after a record $14.7 billion in June, so a $1,000 deposit cap keeps OffMarket small for now.

Polymarket's public ledger has made some traders famous, including a French trader whose large 2024 election bets drew global attention, The Block noted. StarkWare OffMarket is pitched at bettors who would rather avoid that kind of spotlight.

What's next

Watch whether StarkWare raises the deposit cap and whether Polymarket or regulators respond to privacy wrappers on its order book. StarkWare is pitching the launch as a showcase for Starknet's privacy tools, so usage numbers will matter for the network as much as for the app.

The timing sits awkwardly with congressional attention, including the House Oversight letters on prediction market insider trading. Starknet itself is also in focus after its plan for a quantum-resistant layer 1, and StarkWare OffMarket is its clearest consumer use case so far.