Prediction Market Dominance Index
A composite score measuring market action on Kalshi versus Polymarket. The index combines 24h volume share, liquidity share, and liquidity turnover.
Index Components● Kalshi ● Polymarket
Today's Snapshot
Head-to-head comparison of Kalshi and Polymarket across key metrics.
Note: Breadth metrics (Open Markets, Open Events) are shown for context but are not included in the Dominance Index calculation.
Trends
Historical dominance metrics and venue comparison over time.
Methodology
How we calculate the Dominance Index
The Dominance Index measures where traders are most active across prediction markets. Each venue's share (0-100%) is calculated for three metrics, then combined using the weights below.
The Formula
Index=55%×Volume Share+25%×Liquidity Share+20%×Turnover Share
55%Volume Share
Each venue's 24-hour trading volume divided by total volume across both venues. Weighted highest as recent activity is the strongest signal.
25%Liquidity Share
Each venue's order book depth divided by total liquidity across both venues. More depth means larger trades execute with less slippage.
20%Turnover Share
Each venue's turnover ratio (Volume ÷ Liquidity) divided by total turnover. Measures how actively capital is being deployed.
Example Calculation
Raw Data
Kalshi 24h Volume$2.4M
Kalshi Order Book Depth$1.8M
Polymarket 24h Volume$8.1M
Polymarket Order Book Depth$4.2M
Share Calculations
Kalshi Shares
Volume2.4 / 10.5 = 23%
Liquidity1.8 / 6.0 = 30%
Turnover1.33 / 3.26 = 41%
Polymarket Shares
Volume8.1 / 10.5 = 77%
Liquidity4.2 / 6.0 = 70%
Turnover1.93 / 3.26 = 59%
Turnover = Volume ÷ Liquidity
Weighted Index
Kalshi Index
0.55×23 + 0.25×30 + 0.20×41 = 28.4
Polymarket Index
0.55×77 + 0.25×70 + 0.20×59 = 71.6
Center Around 50 (Even)
28.4 − 50 = −21.6
−22 on the dial (Kalshi side)
71.6 − 50 = +21.6
+22 on the dial (Polymarket side)
Both calculations yield the same magnitude — the index is symmetric around 50.
Market count is excluded—Kalshi has 10x+ more markets, but quantity ≠ activity.