Key takeaway: Liquidity stands as the paramount consideration for anyone trading prediction markets. When liquidity runs deep, traders enjoy compressed bid-ask spreads, rapid order execution, and pricing that accurately reflects true probabilities. Polymarket dominates the landscape with over $1.5B in total traded volume; rival platforms typically operate at substantially lower activity levels.
Prediction market liquidity fundamentally shapes your entire trading journey — influencing both the rates at which you transact and your capacity to unwind holdings swiftly. Regrettably, newcomers often prioritise market selection over liquidity considerations. This article explores why liquidity deserves your primary attention.
What is liquidity?
Within financial markets, liquidity refers to the ease with which an asset can be exchanged without materially altering its price. For prediction markets, three distinct dimensions define liquidity:
- Depth: The quantity of shares available at successive price tiers within the order book
- Spread: The distance separating the highest purchase offer (bid) from the lowest sale offer (ask)
- Volume: The aggregate number of shares traded throughout a specified timeframe
A market displaying 10,000 shares bidding at 48 cents alongside 10,000 shares offered at 50 cents exhibits strong liquidity. Conversely, a market with merely 50 shares on either side separated by a 10-cent gap demonstrates poor liquidity.
Why liquidity matters for traders
Insufficient liquidity inflicts financial damage through multiple mechanisms:
- Wider spreads: You incur higher costs when entering and closing trades
- Slippage: Substantial orders push prices unfavourably in your direction
- Trapped positions: Absence of willing buyers prevents you from liquidating holdings prior to market settlement
- Price inaccuracy: Sparse trading environments generate prices disconnected from genuine probability assessments
How to measure prediction market liquidity
Prior to executing any trade, evaluate these key metrics:
- Order book depth: PolyGram's depth chart enables you to observe the concentration of buy and sell orders
- 24h volume: Elevated trading activity correlates with improved order execution odds
- Number of unique traders: Markets attracting 100+ distinct participants typically furnish adequate liquidity for standard retail positions
- Spread percentage: Target markets maintaining spreads below 3 cents (3%) to minimise transaction expenses
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 simultaneously post matching buy and sell orders, capturing profit through the spread whilst furnishing trading counterparties. Polymarket incentivises these participants via fee reductions and MATIC token distributions. PolyGram's proprietary liquidity engine replicates Polymarket's order flow, guaranteeing PolyGram participants access to equivalent order book depth as those trading directly on Polymarket.
Tips for trading illiquid markets
- Deploy limit orders exclusively — refrain from market orders in sparse conditions
- Distribute sizable positions across multiple price points
- Exercise restraint: place your desired price and await execution rather than accepting unfavourable terms
- Account for timing dynamics — thin markets frequently gain depth as expiration approaches
Trade on the most liquid prediction market platform. Start trading on PolyGram →