The U.S. Equities Security Master dataset provides a comprehensive, centralized reference record for all listed and delisted U.S. equity securities from 2007 to the present. It serves as the authoritative foundation for security identification, classification, and lifecycle tracking across the U.S. equities universe. The dataset includes core descriptive attributes such as industry and sector classification, listing status, and security name and ticker history, enabling accurate tracking of securities through name and symbol changes. Each record is organized around algoseek’s Security ID (SecId), a stable internal identifier that remains unchanged across name and ticker updates. In addition, the Security Master provides cross-references to major industry identifiers, including FIGI and ISIN, supporting interoperability with third-party datasets and internal systems. The dataset is delivered as a single consolidated table and is updated daily to reflect new listings, delistings, and reference-data changes. Complementary Lookup Files are available to resolve tickers and other identifiers to SecId.