Prediction markets posted another strong week, with traders generating billions in notional volume and nearly twelve million total transactions across leading platforms. New data highlights continued growth for Polymarket, Kalshi, Opinion, and emerging competitors as interest in event-based trading accelerates heading into 2026.
This week’s INGAME Prediction Market Growth Report breaks down the latest trends in Open Interest, Transaction Count, Notional Volume, and User Activity.
Open Interest Declines Slightly but Remains Near Record Levels
Total open interest across major prediction platforms finished the week at $659 million, down 7 percent week over week. Kalshi and Polymarket continue to dominate market share with nearly identical levels of capital committed.
Open Interest Rankings
- Kalshi – $304 million
- Polymarket – $295 million
- Opinion – $57 million
- Limitless – $1.07 million
- Myriad – $0.98 million
Kalshi maintains a narrow lead over Polymarket, reflecting strong participation in regulated economic and political markets. Secondary platforms remain far behind the leaders but continue to show consistent activity.
Weekly Transactions Increase as Retail Trading Accelerates
Trading activity rose sharply this week. Combined weekly transactions reached 11.46 million, an increase of 11 percent week over week. Polymarket continues to serve as the most active venue for high-frequency traders.
Transaction Rankings
- Polymarket – 5.87 million
- Kalshi – 4.91 million
- Opinion – 0.37 million
- Limitless – 0.27 million
- Myriad – 0.034 million
Polymarket continues to thrive as a retail-driven platform with strong user engagement, tight spreads, and active political and sports markets. Kalshi remains a close second, fueled by continued growth in regulated economic contracts.
Notional Volume Surges to $3.8 Billion
Prediction markets saw significant capital turnover this week. Total notional volume climbed to $3.8 billion, an increase of 8 percent from the previous period.
Notional Volume Rankings
- Opinion – $1.35 billion
- Polymarket – $1.29 billion
- Kalshi – $1.14 billion
- Limitless – $21 million
- Myriad – $1.2 million
Opinion posted the strongest performance, leading all platforms in notional volume. The platform continues attracting deep liquidity in high-interest political markets, pushing it past both Polymarket and Kalshi for the week.
User Activity Softens Slightly but Remains Elevated
Total weekly active users reached 284 thousand, down 3 percent from the previous week. Polymarket remains the clear leader in user participation, with more than 220 thousand active traders.
User Rankings
- Polymarket – 223K
- Opinion – 31.7K
- Limitless – 26.8K
- Myriad – 2.8K
Despite the slight dip in total users, overall engagement remains significantly higher than earlier in the year.
INGAME Analysis
Prediction markets continue showing strong momentum driven by political events, economic uncertainty, and growing mainstream awareness. Several key trends stand out:
- Polymarket leads in transaction activity and user volume, signaling dominant traction among retail traders.
- Kalshi remains the top platform for Open Interest and continues benefiting from its regulated market structure.
- Opinion posted a breakout week with the largest notional volume across all platforms.
- Limitless and Myriad continue building niche audiences in a rapidly expanding ecosystem.
As prediction markets grow, platforms are becoming more specialized. Retail traders gravitate toward fast-moving markets on Polymarket. Institutions and data-focused traders increasingly utilize Kalshi. Opinion continues carving out a strong presence in politically driven markets.
