Sports prediction markets processed $68.2 billion in notional volume over 30 days as college and NFL football returned, a jump of about 72% from the prior month. Over the same stretch, shares of Flutter and Draftkings sank to their lowest levels in years.
A $68 Billion Month
Combined notional volume in sports and combo contracts across exchanges tracked by Aldrin Research rose from $39.74 billion to $68.18 billion between the 30 days to Aug. 30 and the 30 days to Sept. 29, InGame reported. Notional volume counts every contract at its full $1 payout value, so the figure overstates the money that actually changed hands.
Most of the increase came from combos, the parlay-style contracts that bundle several outcomes into one bet. Combo volume more than doubled, from $18.3 billion to $41.7 billion, making up 82% of the added volume. Straight sports contracts, by contrast, grew 23%, to $26.5 billion.
Kalshi Still Leads, but Rivals Close In
Kalshi remains the dominant venue. Its sports and combo volume climbed 65%, from $30.2 billion to $50 billion, yet its overall market share fell from 76.1% to 73.4%. The decline was steeper in combos, where Kalshi's share dropped from 93.5% to 83.9% even as its own combo volume more than doubled to $35 billion.
Smaller venues grew faster. Polymarket U.S. volume rose 127% to $8.3 billion, lifting its share from 9.2% to 12.2%. DKeX, Draftkings' own exchange, expanded from $88.7 million to $1.9 billion, overtaking others to rank third in combos. Novig, the sports-only exchange that recently brought on actress Sydney Sweeney as an equity partner, grew 136%, with its share rising from 1.5% to 2%.
Sportsbook Stocks Sink
Flutter, which owns Fanduel, closed at $74.54 on Sept. 30, while Draftkings closed at $19 — the lowest levels for each since March 2020 and April 2023 respectively, InGame reported. Both stocks are down more than 70% from their 2025 peaks.
Flutter's latest drop followed Brazil's ban on online betting; the company said it has stopped operating there to comply. If the ban lasts through year-end, Flutter expects 2026 revenue to fall by about $70 million and adjusted EBITDA by about $20 million, according to its Sept. 28 statement. Jefferies analysts separately estimated that Flutter's online sportsbook gross gaming revenue in New York is on track to fall 39% through the first three weeks of September.
Draftkings CEO Jason Robins said in September that his company's shares fall on good news for prediction markets, even though Draftkings is building its own prediction-market business. Analysts at Citizens pointed to an Outlier survey in which 35% of respondents cited better prices as a reason to choose prediction markets over sportsbooks.
Kalshi, meanwhile, is in advanced talks to raise $1 billion at a $40 billion valuation, Reuters reported. That private valuation would exceed the combined market value of Flutter and Draftkings, which InGame put at about $12.9 billion and $9.8 billion at Tuesday's lows.
Source: Bitcoin.com News
Trading involves risk.
Risk Disclaimer
