Crypto ETF Sentinel — Curated directory of every active US spot crypto ETF issuer, including staking ETFs (100+ entries across 30+ cryptocurrencies). Each entry carries regulatory-stage classification (registration_filed / under_review / launch_imminent / trading / approved / withdrawn), ticker, exchange, owner organisation, and SEC CIK. Pair with paid per-issuer routes (``?cik=`` query param) to drill into comment letters, XBRL financials, or POS AM profiles.