PairBook US Stock & ETF Correlation Snapshot

Weekly-return correlations (1/3/5-year windows), annualized covariance, beta vs SPY, annualized volatility and ETF holdings overlap for 4,700+ US-listed stocks and ETFs. Snapshot of the live dataset at https://www.pairbook.io/ , which refreshes every trading day and serves everything as a free JSON API (https://www.pairbook.io/api/ , no key, CORS enabled, OpenAPI 3.1). Files: symbols.csv (per-asset stats), pairs.csv (52k tracked pairs). Method: Pearson on weekly returns; overlap = sum of minimum common weights from issuer portfolio disclosures. Formulas: https://www.pairbook.io/methodology/ License: CC BY 4.0, attribution with a link back. Not investment advice.