StarkWare's OffMarket Lets Polymarket Traders Hide Which Wallet Funds Their Bets

StarkWare, the company behind the Starknet network, is offering a web app called OffMarket that lets people trade Polymarket's prediction markets without their positions being publicly linked to their main wallet (sources 1, 2). OffMarket's terms of service name StarkWare Industries Ltd. as the operator (source 2).

Polymarket accounts are normally an open book: anyone who finds a wallet address can see what it bet on, when, and how it did. OffMarket's pitch is that users get "the same Polymarket markets, the same order book, and the same odds" while breaking the link between those bets and their identity (source 1).

How it works

• Deposit into a privacy pool. A user signs in with Google or a crypto wallet and deposits USDC. The money goes into a smart contract on Starknet, where zero-knowledge proofs encode the balance and activity as ciphertext readable only with the user's private viewing key (source 1).
• A fresh wallet per bet. For each position, OffMarket derives a new Polygon wallet from the user's signature. That wallet places the order on Polymarket, holds the position and collects any winnings (source 1).
• Bridging. Funds move between Starknet and Polygon over Circle's CCTP, the burn-and-mint bridge for USDC: coins are burned on one chain and minted on the other (source 1).
• Custody. OffMarket says it is non-custodial. Keys are derived in the browser and not transmitted, and there is no OffMarket server or account database; users could recover their derived wallets directly if the app shut down (source 1).

What stays visible, and who can look

The privacy is partial, and the site says so. An observer can still see USDC leaving the Starknet pool for a Polygon address, that address trading on Polymarket, and its positions and profit or loss. What they are not supposed to see is which Starknet account funded it, whether several positions belong to one person, or any tie to the user's main wallet (source 1).

There is also a compliance back door by design: "the auditing entity holds your viewing key in escrow for compliance tracing," the site says (source 1). It does not name that entity.

The terms bar anyone who is a U.S. person or is accessing the site from the United States, and say OffMarket is not created, operated, endorsed or affiliated with Polymarket (source 2). Trades executed through it remain subject to Polymarket's own terms (source 2).

Le Coin's view: this is a wrapper, not a new market, and its value rests on the size of the crowd in the Starknet pool. A small pool makes deposits and withdrawals easier to match up by amount and timing, and the escrowed viewing key means "private" here means private from the public, not from a compliance auditor. It also runs at Polymarket's tolerance, since Polymarket doesn't operate or endorse it.

Holding the Corner.

Not financial advice.