Examples of ISO standards in market data would be?

• A. The definition of a market closing price
• B. The number of days after yearend that a corporation must report its financial statements
• C. ISO Standards for FIX, Corporate Actions and the LEI
• D. ISO Standards for market data definitions and interfaces

Answer: (D)

ISO standards in market data establish common definitions and data formats so that prices, identifiers, and messages mean the same thing wherever they’re used. This kind of standardization makes data interoperable across venues, vendors, and systems, which is essential for reliable feeds and accurate analytics. The idea of ISO standards for market data definitions and interfaces captures this framework—the global guidance on how data should be defined and how messages should be exchanged.

Defining a market closing price is a specific data point, not a standardized framework. Regulatory timelines for financial reporting are not ISO standards—they’re regulatory requirements. The choice that mixes FIX, Corporate Actions, and the LEI is misleading because FIX is not an ISO standard, and while LEI is an ISO standard, the statement as a whole doesn’t reflect the ISO-standardized approach to market data definitions and interfaces.