The Open Stablecoin Index ($OPEN) is an equal-weight index tracking leading stablecoin-networks advancing transparency, composability, and user-led governance. Included protocols are be evaluated on verifiable asset-backing, peg design, mint/redeem logic, safety mechanisms, yield-sharing, and decentralized control. Stablecoins have exploded, yet they only make up just ~1% of the $22T U.S. M2—and touch only 1.3% of Earth each month. The Open Stablecoin Index is here to track the frontier: part index, part knowledge graph, part coordination layer.