Avoiding Double Counting in Polymarket Volume Data
Summary
The article explains why summing every Polymarket OrderFilled event overstates trading volume. Each transaction emits maker-focused events for individual counterparties and a taker-focused event that summarizes the same fills. The exchange contracts route token transfers but do not take positions or become trade counterparties, so the event records represent overlapping views of activity rather than separate trades. The article recommends counting one side consistently, such as taker-side or maker-side volume.
It also explains why matched orders can span YES and NO books and involve split or merge operations, making individual token flows look imbalanced in block explorers. Its analysis combines event sequences, exchange contract behavior, and market structure, and cites validation with data analysts and dashboard providers. It concerns raw volume accounting and comparison across prediction-market platforms; it does not address wash trading, volume quality, or whether volume predicts prices. The article discloses that its publisher invests in a competing platform.
Key ideas
- Maker-focused and taker-focused OrderFilled events can describe the same economic fills.
- Summing both sets of OrderFilled events double counts contracts and cash flow.
- Volume should be measured from one side of each trade, using a consistent maker-side or taker-side method.
- YES and NO matching, including split and merge operations, can make individual transaction flows appear unbalanced.
- Understanding the event stream requires combining contract behavior with market structure rather than relying on block explorer summaries.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.