MARKET DATA

Freshness

Measured source age, labels, and engine gates.

#Thresholds

AgeLabelEngine
≀15sLIVEEligible
16–45sUPDATED nS AGOEligible within max policy
46–90sDATA DELAYEDEligible only until policy limit
>90sSTALERejected
Any age + haltMARKET HALTEDRejected

#Two timestamps

generatedAt belongs to the upstream response. fetchedAt is when the application completed its snapshot. Their difference is the source age at receipt.

#Client refresh

Queries retain the last verified snapshot during a refresh. A failed refresh marks it delayed rather than rewriting values as zero.

#Clock assumption

Freshness depends on clocks and upstream timestamp correctness. Operators should monitor system time.