Most prediction-market screeners rank by volume. Volume tells you what already happened; liquidity tells you what you can do now. These are the 30 Polymarket markets with the deepest standing order books — the markets where you can place a $1K position and barely move the mid.
Top 30 Markets by Liquidity
| # | Market | Category | Liquidity | Volume |
|---|---|---|---|---|
| #1 | US x Iran ceasefire by April 7? | politics | $20.0M | $173.3M |
| #2 | Russia x Ukraine ceasefire by May 31, 2026? | politics | $15.5M | $126.7M |
| #3 | Netanyahu out by March 31? | politics | $14.7M | $104.2M |
| #4 | US forces enter Iran by March 31? | geopolitics | $13.8M | $73.9M |
| #5 | Will the Fed decrease interest rates by 50+ bps after the April 2026 meeting? | economics | $12.8M | $62.9M |
| #6 | Will "Donk" be said during the PGL Bucharest 2026 Grand Final? | other | $12.5M | $5.6M |
| #7 | Will Panama win the 2026 FIFA World Cup? | sports | $11.0M | $17.5M |
| #8 | Will Iraq win the 2026 FIFA World Cup? | sports | $11.0M | $16.5M |
| #9 | Will Tunisia win the 2026 FIFA World Cup? | sports | $11.0M | $27.9M |
| #10 | Will Haiti win the 2026 FIFA World Cup? | sports | $10.9M | $20.1M |
| #11 | Will Bosnia-Herzegovina win the 2026 FIFA World Cup? | sports | $10.8M | $13.9M |
| #12 | Will Qatar win the 2026 FIFA World Cup? | sports | $10.7M | $29.3M |
| #13 | Will Cape Verde win the 2026 FIFA World Cup? | sports | $10.7M | $27.5M |
| #14 | Will Jordan win the 2026 FIFA World Cup? | sports | $10.6M | $30.4M |
| #15 | Will Curaçao win the 2026 FIFA World Cup? | sports | $10.4M | $40.4M |
| #16 | Will New Zealand win the 2026 FIFA World Cup? | sports | $10.2M | $35.2M |
| #17 | Will Algeria win the 2026 FIFA World Cup? | sports | $10.1M | $26.8M |
| #18 | Will Ghana win the 2026 FIFA World Cup? | sports | $9.7M | $24.3M |
| #19 | Will Canada win the 2026 FIFA World Cup? | sports | $9.7M | $29.5M |
| #20 | Will Saudi Arabia win the 2026 FIFA World Cup? | sports | $9.6M | $32.5M |
| #21 | Will Australia win the 2026 FIFA World Cup? | sports | $9.2M | $29.9M |
| #22 | Military action against Iran ends by April 17, 2026? | geopolitics | $8.7M | $28.7M |
| #23 | Will Scotland win the 2026 FIFA World Cup? | sports | $8.6M | $30.3M |
| #24 | Will Egypt win the 2026 FIFA World Cup? | sports | $8.6M | $30.0M |
| #25 | Will Czechia win the 2026 FIFA World Cup? | sports | $8.4M | $12.6M |
| #26 | Will Sweden win the 2026 FIFA World Cup? | sports | $8.3M | $16.2M |
| #27 | Epstein suicide note released by May 8? | entertainment | $8.1M | $13.4M |
| #28 | Will South Africa win the 2026 FIFA World Cup? | sports | $7.8M | $33.2M |
| #29 | Will the Fed decrease interest rates by 50+ bps after the March 2026 meeting? | economics | $7.7M | $173.2M |
| #30 | Will Paraguay win the 2026 FIFA World Cup? | sports | $7.5M | $26.1M |
Liquidity = sum of resting orders within 5¢ of mid on both sides. Captured 2026-06-10 from the Protodex dataset.
Volume / Liquidity Ratio — A Cleaner Signal
A high volume-to-liquidity ratio means the market is being traded faster than market makers can replenish — a sign of fresh information. A low ratio means the order book is full but no one's hitting it — typical of stale or boring markets. The full dataset (with 15-minute orderbook snapshots) lets you watch this ratio over time. Get the dataset →
Practical Takeaway
- Sizing rule: Position size ≤ 5% of one-sided liquidity, or you eat 1-3¢ of slippage on entry and exit. On a 50¢ market that's a 4-6% drag — fatal for most edges.
- Bid-ask spread floor: Anything above 3¢ wide is paying market makers' rent, not capturing edge.
- Liquidity decay: Markets bleed liquidity as resolution approaches. The widest spreads are usually 1-3 days from settlement.
📊 The Full Polymarket Historical Dataset
10.8M+ price snapshots across 13,900+ prediction markets. 15-minute frequency, orderbook depth, 43+ days of data. Use the same source data behind this post for your own backtests, models, and research.
Get the dataset →