# Prediction Market Volume by Platform

> Prediction market volume compared across platforms: weekly and monthly volume, on-chain share, Polymarket and Kalshi side by side and volume by category.

Markdown copy of https://voltfincrypto.com/apps/prediction-market-volume

**Question:** How much volume does each prediction market platform handle, and what share is settled on-chain?

- Kind: Dashboard in Voltfin Vantage
- Topic: [Markets and trading](https://voltfincrypto.com/topics/trading)
- Chains: Multi-chain, Polygon, Base, BNB Chain, Solana
- Status: Planned. The data is not published yet, so this page states no figure; each figure will open its receipt when it is.

Prediction markets let traders buy shares in the outcome of an event, from elections and sports to economic data and crypto prices. Some settle every trade on a public chain, such as Polymarket on Polygon; others, such as Kalshi, run as regulated exchanges that publish their own figures. This dashboard puts their volume side by side.

On-chain volume is read from each venue's contracts and counted once per trade. Off-chain volume is taken from what each platform publishes and labelled as reported. Platforms also define volume differently, some as the full payout value of the contracts traded and some as the money paid for them, so each series names its definition and the comparison uses one basis wherever both are available.

Use it to see how the market splits between platforms, how much of it settles on-chain and which event categories, from sports to elections, draw the most trading week to week.

## Blueprint

### Platforms

Volume by platform each week and month, on one definition.

- **Volume, last week** (USD): Volume across every covered platform over the last complete week, on the selected basis.
- **Settled on-chain** (%): Share of last week's volume across covered platforms that settled on public chains.
- **Polymarket, last week** (USD): Polymarket's volume over the last complete week, counted once per trade.
- **Kalshi, last week** (USD): Kalshi's volume over the last complete week as the platform publishes it, put on the selected basis.
- **Volume by platform** (USD): Weekly volume per platform, stacked, with on-chain venues and off-chain exchanges shaded apart.
- **Market share over time** (%): Each platform's share of weekly volume over the selected period, on the selected basis.

### Categories

What the volume is traded on, across platforms.

- **Largest category's share** (%): Share of last week's volume traded in its largest category across platforms.
- **Platforms covered** (count): Platforms with recorded volume in the last complete week, on-chain and off-chain.
- **Volume by category** (USD): Weekly volume split into sports, politics, economics, crypto and other categories.
- **Platforms compared**: Each platform's chain or regulator, volume definition, last week's volume, monthly volume and source.

Filters: Volume basis (Notional or premium); Period (Last 12 or 52 weeks, or by month).

## How it will be measured

- Polymarket volume is the collateral value of matched trades from its exchange contracts on Polygon, counted once per match from the taker's fill.
- Other on-chain venues on Base, BNB Chain and Solana are read from their trade-fill events with the same once-per-trade rule.
- Off-chain platforms' volume is what each platform publishes, recorded with its source, its time window and whether it counts notional or premium.
- Where one platform reports notional and another premium, both are put on the same basis using each trade's price where trades are public, and the conversion is marked.
- The on-chain share divides on-chain volume by the total of every covered platform, on the same basis and in the same week.

## Data it needs

- `prediction_markets_daily` (to build): Volume, open interest and traders per prediction market and category per day.
- Source: Polymarket CTF Exchange and NegRisk CTF Exchange OrderFilled events on Polygon, and the exchange contracts that replaced them
- Source: Trade-fill events of on-chain prediction market contracts on Base, BNB Chain and Solana
- Source: Platform-published volume for off-chain regulated exchanges such as Kalshi (off-chain)
- Source: Each platform's volume definition, notional or premium, recorded per source
- Source: Market categories from each platform's public market data (off-chain labels)

## Questions

### What is prediction market volume?

It is the value of outcome shares traded on a platform over a period. Because platforms count it differently, as the payout value of contracts or the money paid for them, figures are comparable only on the same definition.

### Which is bigger, Polymarket or Kalshi?

The answer changes from week to week and depends on the definition used. This dashboard shows both platforms on the same basis for every week, so the comparison can be read directly from the chart.

### Are prediction markets on-chain?

Some are. Polymarket and several smaller venues settle trades on public chains, so their volume can be read from contracts. Regulated exchanges such as Kalshi keep their order books off-chain and publish their own volume figures.

### What do people bet on in prediction markets?

Sports, politics, economics, crypto prices, culture and world events are the main categories. Category labels come from each platform's market data and are shown as a share of volume per week.

### Why can prediction market volume be double counted?

On some exchanges each matched trade produces a record for the taker and one for each maker. Adding every record counts the trade twice. This dashboard counts each trade once.

## Glossary

- **Notional volume**: Volume measured at the payout value of the contracts traded, whatever price was paid for them.
- **Premium volume**: Volume measured as the money actually paid for outcome shares: the share price times the number of shares.
- **Event contract**: A contract that pays a fixed amount if a defined event happens and nothing if it does not.

## Related apps

- [Polymarket Volume and Open Interest Tracker](https://voltfincrypto.com/apps/polymarket-volume-open-interest)
- [Perp DEX Volume and Market Share by Venue](https://voltfincrypto.com/apps/perp-dex-volume-market-share)
- [DEX Volume by Chain and Protocol](https://voltfincrypto.com/apps/dex-volume-by-chain)
- [Crypto Liquidations Today: Longs vs Shorts](https://voltfincrypto.com/apps/crypto-liquidations-today)
- [Liquidation Heatmap from On-Chain Positions](https://voltfincrypto.com/apps/liquidation-heatmap)
- [Airdrop Claim Tracker: Claimed vs Unclaimed](https://voltfincrypto.com/apps/airdrop-claim-tracker)

Build it in Voltfin Studio: https://app.voltfincrypto.com/signup?next=%2F