{"success":true,"engine":"Black Belt Labs","metric_id":"M10036","name":"Bridge Concentration Index","category":"onchain","classification":"classic","update_frequency":"daily","inputs":["Curated reference data","On-chain data"],"inputs_are":"types of input","lookback_windows":["31 DAY"],"lookback_basis":"windows found in the implementation (INTERVAL clauses)","formula":"Herfindahl index of 30-day flow shares across BBL's tracked L2 bridge contracts (Base, Optimism, zkSync, Polygon), normalized 0 (even) to 100 (single bridge). High concentration = more value exposed to a single bridge's failure - the H10053 blast-radius gauge. Declared fixed four-bridge set.","formula_published":true,"definition_version":"1.0","definition_history":[{"version":"1.0","effective_from":"2026-09-10T09:20:11Z","change_note":"initial recorded definition"}],"methods":["progr","quant-hw","quant-sim"],"disclaimer":"Madjik metrics are informational market indicators computed by Black Belt Labs. They are not investment advice, an offer, or a recommendation to buy or sell any asset."}