StarkWare opened OffMarket to the public on October 14, 2026, a privacy service that lets traders use Polymarket without publicly linking their positions to their existing accounts, according to The Block in a report published on October 14, 2026. The service had been in limited early release since August 2026, The Block reported, and MetaversePost reported the same public launch on October 15, 2026, describing OffMarket as a zero knowledge tool running on Starknet.
The problem OffMarket targets is Polymarket's public record. Polymarket records trades on Polygon, so anyone can examine an account's positions, order sizes and trading history, according to The Block. Blockchain analysts linked several accounts in 2024 to a French trader who had placed tens of millions of dollars on Donald Trump winning the United States presidential election, and Bloomberg identified at least 34,000 trades flagged as possible insider activity between August 2025 and June 2026, The Block reported.
The mechanism is a shared privacy pool, not a separate market. Deposits are capped at 1,000 USDC per account, a StarkWare spokesperson told The Block, with plans to adjust the limit according to demand and usage. Orders execute on Polymarket itself, against the same buyers and sellers and at the same market prices, the spokesperson said. The pool OffMarket shares holds around 1.5 million dollars across 17,000 deposits, according to L2BEAT figures cited by StarkWare and reported by The Block, and private orders take about a minute to execute while withdrawals take a few minutes, the spokesperson said.
Each position gets its own wallet. A trader signs in with Google or a crypto wallet and deposits USDC, and OffMarket derives a fresh Polygon trading wallet for each position from the user's signature, according to AltcoinBuzz in an October 15, 2026 review based on OffMarket's own description. Funds move in two stages in that account: deposits enter a Starknet contract where zero knowledge proofs encode balance and activity, then Circle's CCTP bridge burns the USDC on Starknet and mints it to the fresh Polygon wallet, carrying no identifying information, AltcoinBuzz reported.
Custody and compliance are split by design. OffMarket is fully non-custodial, with users retaining control of their keys in their browsers and able to recover wallets from their signatures if the service went offline, the spokesperson told The Block. OpenZeppelin audited the pool contract in June 2026 and reported no critical or high severity findings, and StarkWare formally verified the contract in July 2026, according to The Block. Separately, AltcoinBuzz reported that the OpenZeppelin report dated June 23, 2026 logged 11 findings, zero critical and zero high, with both medium issues resolved.
A compliance firm can still see in, under conditions. Independent firm Financial Privacy Inc. keeps the master viewing key inside a secure enclave, screens deposits against sanctions lists, and its counsel reviews requests for transaction information from courts, regulators and agencies, according to The Block. The firm can refuse a request whose legal basis it cannot verify, the spokesperson told The Block, and it releases only information covered by an approved request under a multisignature arrangement with StarkWare.
The limits are explicit, and so is the distance from Polymarket. OffMarket is not a Polymarket product, has no formal partnership or special access, and takes part in Polymarket's verified builder program, which Polymarket can disable, the spokesperson told The Block. It applies Polymarket's geographic restrictions, including the ban on United States users, and it cannot stop identification through transaction size or timing, because transfers from the pool to a fresh wallet and the trades themselves remain public, according to The Block. StarkWare co-founder and chief executive Eli Ben-Sasson, a founding scientist of Zcash, tied the project to his earlier privacy work in a statement reported by The Block, saying that conviction that privacy matters drives the team.
Analysis: OffMarket tests the trade at the center of onchain prediction markets. Public records are why outsiders could flag 34,000 possible insider trades on Polymarket, and they are also why a trader with a legitimate information edge, human or automated, exposes strategy, size and timing to every competitor watching the chain. OffMarket hides the funding link and keeps the trade itself public, which preserves price discovery while weakening the surveillance trail that made the insider flags possible. What to watch is scale and permission: whether StarkWare raises the 1,000 USDC cap, whether the shared pool grows well past 1.5 million dollars and 17,000 deposits so the anonymity set is real rather than theoretical, whether Polymarket leaves the builder code enabled, and whether the Financial Privacy Inc. viewing key arrangement is ever tested by a court or regulator. At the current cap, volumes were small by design in the early release, according to The Block, so the launch is an infrastructure signal first and a market force only if those limits lift.