← All oracles
UUMA
#7 by TVSOptimisticToken: UMASince 2020
Optimistic oracle for arbitrary truth — the settlement layer behind Polymarket.
- Type
- Optimistic
- How it works
- Assert-and-dispute: any data is proposed, can be challenged within a window, and is settled by a token-holder vote (the DVM) only if disputed.
- Chains
- Ethereum + L2s — Ethereum and major L2s.
- Feeds
- Arbitrary data — Any verifiable claim — not just prices.
- Security
- Economic security via bonding, a dispute window and UMA-holder voting.
- TVS*
- Event-driven
- Token
- UMA
- Notable users
- Polymarket, Across, insurance protocols
* Approximate total value secured — a dated market snapshot (DefiLlama / provider reports, 2026), not a live figure.
Best at
Subjective / arbitrary data: prediction-market resolution, insurance, custom claims a price feed can’t express.
Powers Polymarket settlement and cross-chain bridges (Across).
Strengths
- Can verify ANY claim, not just prices
- Cheap when undisputed
- Ideal for prediction markets & insurance
Trade-offs
- Latency from the dispute window
- Not suitable for real-time price feeds
- Depends on honest-majority governance
Read the UMA docs →
Compare UMA with…