TQBTHEQUANTBATEMAN
TQB/ learn/ foundations/ streaming quotes and stalenessEN · DARK
Foundationspractitionermethod

Streaming Quotes and Staleness

Treat market data as a timed state, not a timeless number.

Reviewed 2026-08-10TheQuantBateman ResearchReading note
01Intuition

Build the mental model first.

A stream changes a quote over time. Heartbeats, reconnects and freshness thresholds tell the interface when to stop calling the last value current.

ONE-LINE DEFINITION

Treat market data as a timed state, not a timeless number.

02Mathematics

Now make it exact.

age=tnowtmarket,stale=1age>τage=t_{now}-t_{market}, \quad stale=\mathbf{1}_{age>\tau}
Notation and units

Decimal rates and volatilities, year-fraction time and continuous compounding unless stated otherwise.

03Assumptions

Every model has a price.

01

Educational conventions are stated explicitly and may simplify market quotation or settlement details.

02

Rates are continuously compounded unless the section says otherwise.

03

Inputs are deterministic in the base model.

“An unstated convention is a future reconciliation break.”— THEQUANTBATEMAN
04Market use

Why a quant cares.

Prevents stale values from silently driving risk, calibration or user decisions.

IntuitionMathematicsImplementationDesk risk
05Desk view
FRONT OFFICE VIEW

The hedge has opinions.

Start with the quote convention, then ask which Foundations risk survives the hedge. A number without its convention is merely well-dressed ambiguity.

Ask Bateman about this model
06Related

Continue through the graph.