TQBTHEQUANTBATEMAN
TQB/ learn/ foundations/ prediction market liquidity open interest and volumeEN · DARK
Foundationspractitionermarket-note

Prediction Market Liquidity Open Interest and Volume

Separate trading activity, outstanding exposure and available book depth.

Reviewed 2026-08-10TheQuantBateman ResearchReading note
01Intuition

Begin with the executable market object.

Volume measures turnover, open interest measures outstanding exposure, and liquidity describes the ability to trade without moving price. They answer different questions.

ONE-LINE DEFINITION

Separate trading activity, outstanding exposure and available book depth.

02Mathematics

Make the quote arithmetic explicit.

volume=∑∣qtrade∣,OI=outstanding exposure,depth(ϵ)=∑∣p−mid∣≤ϵqvolume=\sum |q_{trade}|, \quad OI=\text{outstanding exposure}, \quad depth(\epsilon)=\sum_{|p-mid|\le\epsilon}q
Notation and units

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

03Assumptions

Record venue, timestamp, and convention.

01

The venue, timestamp, executable side and data status are part of every market observation.

02

Midpoints and derived probabilities are analytical coordinates, not guaranteed executable levels.

03

Licensing, freshness and resolution rules determine how the observation may be used.

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

Distinguish observation from inference.

Screening active events, qualifying probability signals and comparing market quality.

Intuition→Mathematics→Implementation→Desk risk
05Desk view
FRONT OFFICE VIEW

Ask what can actually be traded or hedged.

Start from the executable side and timestamp. Derived Foundations signals are only as reliable as the market state and resolution convention beneath them.

Ask Bateman about this topic →
06Related

Inspect the connected market state.