In this guide
Key takeaway: Liquidity stands as the paramount consideration for prediction market participants. When liquidity runs deep, you benefit from compressed spreads, instantaneous execution, and fair market pricing. Polymarket dominates the landscape with $1.5B+ in total traded volume; alternative venues typically deliver substantially less depth.
Prediction market liquidity shapes your entire trading journey — dictating entry costs, exit velocity, and position management flexibility. Yet newcomers routinely overlook liquidity depth and concentrate instead on market selection. This resource unpacks why liquidity fundamentals outweigh all other considerations.
What is liquidity?
Within financial trading ecosystems, liquidity reflects the ease with which you can transact an asset without materially shifting its quoted price. For prediction markets, three pillars define liquidity:
- Depth: The quantity of shares resting at successive price tiers throughout the order book
- Spread: The distance separating the highest buyer's offer from the lowest seller's asking price
- Volume: The aggregate share count transitioning hands within a specified timeframe
A market displaying 10,000 shares bid at 48 cents alongside 10,000 shares offered at 50 cents demonstrates robust liquidity. Conversely, 50 shares on either side with a 10-cent gap signals severe illiquidity.
Why liquidity matters for traders
Insufficient liquidity erodes your profitability through multiple channels:
- Wider spreads: Transaction costs balloon when entering and closing trades
- Slippage: Substantial position sizes push pricing unfavourably during execution
- Trapped positions: Absence of willing counterparties prevents exit before market settlement
- Price inaccuracy: Sparse trading environments produce quotations misaligned with genuine probabilities
How to measure prediction market liquidity
Evaluate these metrics prior to committing capital:
- Order book depth: PolyGram's depth visualisation reveals cumulative buy and sell pressure across price levels
- 24h volume: Elevated turnover correlates with execution certainty — faster fills for standard positions
- Number of unique traders: Markets attracting 100+ distinct participants typically furnish adequate liquidity for standard retail exposure
- Spread percentage: Target venues where spreads remain beneath 3 cents (3%) to minimise transaction drag
Which platforms have the most liquidity?
| Platform | Cumulative volume | Avg. spread |
| Polymarket | $1.5B+ | 1-3 cents |
| Kalshi | $500M+ | 2-5 cents |
| Betfair Exchange | N/A (sports-focused) | 1-2% on sports |
| Augur/Azuro | $50M+ | 5-15 cents |
How market makers create liquidity
Institutional liquidity providers deploy paired buy-sell orders simultaneously, capturing spread differential whilst supplying counterparty availability to the broader trader base. Polymarket compensates these operators through fee reductions and MATIC incentive structures. PolyGram's proprietary liquidity aggregation synchronises with Polymarket's order flow, guaranteeing PolyGram participants access identical book depth as native Polymarket users.
Tips for trading illiquid markets
- Deploy limit orders exclusively — avoid market execution in sparse order books
- Segment substantial positions across multiple price points
- Exercise restraint: anchor your bid and permit the market to reach your target rather than accepting unfavourable fills
- Factor in temporal dynamics — thin markets frequently consolidate liquidity approaching settlement
Participate on the highest-liquidity prediction market ecosystem. Start trading on PolyGram →