Proof of Market Consistency (PoMC) A Proper-Scoring Mechanism for Decentralized Oracle Resolution

Abstract

Decentralized applications often require reliable information about external events whose outcomes are uncertain at the time of reporting but verifiable after settlement. Existing oracle mechanisms typically rely on trusted data providers, token-weighted voting, staking, dispute games, or prediction-market incentives. These approaches may allocate influence according to wealth, identity count, or discrete votes rather than calibrated informational quality. This paper introduces Proof of Market Consistency (PoMC), an information-weighted oracle mechanism for decentralized event resolution. Admitted reporters submit probabilistic forecasts about event outcomes. Reports are evaluated ex post using strictly proper scoring rules, and each reporter accumulates information capital through a multiplicative update rule based on predictive performance. Oracle outputs are obtained by aggregating reports with information-capital weights. We establish four main properties. First, strictly proper scoring rules provide one-shot incentives for truthful probabilistic reporting. Second, under stationary reporting performance, information capital concentrates on the most accurate reporters while uninformative reporters lose influence. Third, the update rule admits an online-learning interpretation and yields a sublinear regret bound relative to the best reporter in hindsight. Fourth, because purely reputation-based systems are vulnerable to Sybil attacks, we introduce a minimal stake-gated admission rule that bounds identity creation while leaving oracle influence determined by predictive accuracy. PoMC is not a replacement for block-level consensus protocols. Rather, it is a properscoring and online-learning layer for decentralized oracle resolution. The mechanism separates economic admission from informational authority: stake limits identity creation, while calibrated predictive performance determines influence.