Similar exposure, different contracts
An index value is not an ETF share. Keep the underlying reference and the option product family explicit, including each contract’s exercise style, multiplier and settlement method. Cboe identifies SPX options as cash-settled and European-style; this is a product-specific example, not a rule to impose on every index-related instrument.
Use several clocks
Last trading time, expiration and settlement observation are separate events. Preserve the timezone and the precision actually provided by the source. A date-only record should stay date-only until a reliable specification resolves the time. Version the calendar logic used to create any derived timestamps.
Keep settlement out of the live-price field
A final settlement observation needs its own source, applicable contract and status. Do not replace a pending settlement value with the most recent index close simply because it produces a complete-looking table. The related article shows how a calendar-aware record prevents this ambiguity in a research system.
Read the state transition
A practical monitor can distinguish active, trading ended, awaiting settlement, settled and unresolved states. These are proposed application labels that require explicit mappings to your source. They help a reader see the difference between a market event and an incomplete update rather than treating every blank cell alike.
