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59 Sports Prediction Market Statistics

by Guy Bruhn

Kalshi and Polymarket have turned sports event contracts into a major trading category. A new report by Doc's Sports reveals 59 statistics that track their growth, sports footprint, trading activity, market coverage, fees and unsettled regulatory position.

Kalshi and Polymarket have become major destinations for sports trading, with football helping generate some of their largest volume spikes. Readers looking to compare prediction-market prices with traditional matchup analysis can also review Doc’s Sports’ Expert NFL picks.

Prediction Market Growth

Prediction markets moved decisively into the sports mainstream in 2026, with Kalshi taking the volume lead while Polymarket continued to offer a broad global menu.

  1. Kalshi recorded $256.8 billion in contract volume in 2026 through Oct. 6.
  2. September was Kalshi's strongest completed month of 2026.
  3. September volume was 52% higher than August.
  4. September 2026 volume was 2,020% higher than in September 2025.
  5. Kalshi represented 76.3% of tracked prediction-market volume in September.
  6. Kalshi traded $66.7 billion in contracts during the 30 days ending Oct. 6.
  7. Traders paid $15.9 billion for those contracts, illustrating why face-value contract volume and dollars spent should not be treated as the same metric.
  8. Kalshi's volume for the week of Sept. 28 through Oct. 4 reached $18.37 billion.
  9. That weekly total represented 76.7% of volume across the venues tracked by DeFi Rate.
  10. Kalshi's 2026 annualized trading volume rose from $52 billion to $178 billion over a six-month period, according to the company.
  11. Kalshi said institutional trading volume increased 800% over the same six-month period.
  12. Polymarket recorded approximately $21.5 billion in 2025 volume, compared with roughly $17.1 billion for Kalshi.
  13. Kalshi's 2025 volume increased 1,108% year over year.
  14. Together, Kalshi and Polymarket were estimated to account for 85% to 90% of global prediction-market volume in 2025.
  15. Polymarket recorded $72.9 billion in contract volume in 2026 through Oct. 6 under DeFi Rate's standardized contract-counting methodology.
  16. June was Polymarket's strongest completed month of 2026, with $11.3 billion in contract volume.
  17. During the 30 days ending Oct. 6, Polymarket generated $4.7 billion in contract volume and $2.3 billion in dollars paid.
  18. Polymarket represented 5% of tracked prediction-market volume during that 30-day period.

Sports Takes Over

Sports is no longer a side category for prediction exchanges. It is a core source of listings, volume and fees, particularly when parlays and other combination contracts are included.

  1. Kalshi's sports category traded $15.9 billion in contracts during the 30 days ending Oct. 11, up 16.8% from the prior 30 days.
  2. Sports was 21.8% of Kalshi's contract volume in that window, while multi-leg combos drew $4.3 billion in dollars paid, 25% of all dollars paid on the exchange.
  3. Kalshi's sports category generated $3.64 billion during the week of Sept. 28 through Oct. 4, up 1.31% from the prior week.
  4. Football-tagged markets produced $1.37 billion that week, up 7.2%, while soccer jumped 40.7% to $452.6 million and baseball fell 32.6% to $362.1 million after the MLB regular season ended Sept. 27.
  5. The week's largest single market was a 10-leg NFL combo with $117.16 million in volume, followed by a 10-leg college-football combo at $102.68 million.
  6. Kalshi's Exotics category, which holds its parlays, reached $11.82 billion that week, or 64.3% of the exchange's total volume.
  7. Kalshi posted its first $3 billion day on Sept. 20, 2026, at $3.17 billion, during a week in which its sports category traded $3.24 billion.
  8. Monthly Kalshi sports volume grew 18-fold in three quarters, from $540 million in July 2025 to $9.9 billion in March 2026, according to Blockworks Research.
  9. Basketball accounted for 44% of Kalshi's sports volume, football 28% and tennis 10%, with Kalshi handling roughly 70% of all prediction-market sports volume.
  10. Through June 15, 2026, Kalshi's sports category had traded $73.9 billion across 1,949 markets and its Exotics category another $20.9 billion, about 85% of a roughly $112 billion lifetime total, according to Dune Analytics data compiled by SGI Europe.
  11. The week ending June 15, 2026 brought $8.99 billion in volume, 86.9% of it sports, more than all of Kalshi's 2023 volume combined.
  12. Sports accounted for roughly 80% of Kalshi's fee-generating volume in June, according to Sacra's estimates.
  13. Kalshi's August combo volume reached $17.84 billion, or 44.6% of total monthly volume.
  14. Non-combo sports supplied another 33.9% of Kalshi's August total.

Sports And Leagues

Football generates large weekly spikes, but baseball, soccer, tennis, basketball and international competitions keep prediction exchanges active throughout the year.

Prediction-market prices show how traders collectively view a game, but they are only one part of the betting picture. Injuries, line movement, recent performance, and individual matchups also matter when evaluating weekly Expert NFL picks.

  1. Kalshi's 2026 World Cup winner market had already exceeded $130 million in volume by June 11.
  2. Tennis volume on Kalshi was up 25-fold year over year when the platform announced its U.S. Open partnership.
  3. Kalshi became the exclusive prediction-market partner of the U.S. Open beginning with the 2026 tournament.
  4. Kalshi's preseason NFL game markets had already generated $333 million by the end of August.
  5. Polymarket displayed approximately 26,200 sports markets in early October.
  6. Roughly half of Polymarket's displayed sports inventory, 13,100 markets, fell under its "Games" grouping.
  7. Soccer was Polymarket's largest displayed sport or league grouping, with approximately 10,000 markets.
  8. The platform displayed 755 esports markets.
  9. It displayed 558 NFL markets.
  10. It displayed 533 college-football markets.
  11. It displayed 508 tennis markets.
  12. It displayed 211 NHL markets.
  13. It displayed 204 English Premier League markets.
  14. It displayed 119 MLB markets.
  15. Polymarket's 2026 MLB World Series winner market had generated approximately $43 million in volume by early October.
  16. Its 2027 NBA championship market had generated approximately $24 million.
  17. Polymarket's 2027 UEFA Champions League winner market had generated approximately $29 million.
  18. A single live Brewers-Padres MLB event showed $1.53 million in volume during the ninth inning.

Trading Activity

The platforms attract millions of trades and users, but volume is concentrated among heavy users and automated accounts.

  1. Polymarket processed 43.2 million trades during the 30 days ending Oct. 6, or approximately 1.4 million per day.
  2. The average dollars paid per Polymarket trade during that period was $55.17.
  3. Research covering 2.4 million Polymarket users and $67 billion in volume found that 68.8% of users lost money.
  4. The top 1% of traders captured 76.5% of all gains in that research.
  5. Approximately 5% of bot-like wallets generated 75% of Polymarket volume, according to a Bloomberg analysis.
  6. Kalshi said three out of four users visit its markets for information without placing a trade.
  7. On Kalshi's 2026 midterm markets, viewers outnumbered traders five to one.

Fees And Regulation

These exchanges resemble sportsbooks to many users, but they operate through dollar-denominated event contracts and face an unsettled mix of federal oversight and state litigation.

  1. Kalshi was designated by the CFTC as a contract market on Nov. 3, 2020, while QCX, operating as Polymarket US, received its designation on July 9, 2025.
  2. By September 2026, at least three federal appeals courts had reached different conclusions about whether state gambling laws could apply to prediction-market sports contracts, leaving a regulatory split that could ultimately require Supreme Court review.

References

  1. Games Prediction Markets & Live Odds 2026 — Polymarket
  2. Kalshi Booms on Sports — SGI Europe, Dune Analytics data through June 15, 2026
  3. Kalshi Volume: Daily, Weekly & Monthly Data Charts — DeFi Rate
  4. Polymarket Trading Volume: Updated Daily with Charts — DeFi Rate
  5. Kalshi: $1 Billion Series F Raised At $22 Billion Valuation — Pulse 2.0
  6. Prediction Markets Hit $44 Billion Volume as Polymarket, Kalshi Compete — TokenPost
  7. Kalshi revenue, valuation & funding — Sacra
  8. Parlays Explode Amid Dead Sports Calendar — Cap Space
  9. Kalshi tops $40bn+ volume for 2nd month as parlays drive growth — nextpredict
  10. Big prediction numbers, and the search for an analog that makes sense of them — Cap Space
  11. 48 teams, 1 winner: Kalshi's 2026 World Cup roundup — Kalshi, June 11, 2026
  12. Kalshi Expands Tennis Presence With US Open Partnership — Covers, Aug. 31, 2026
  13. CFB (All) Prediction Markets & Live Odds 2026 — Polymarket
  14. MLB Prediction Markets & Live Odds 2026 — Polymarket
  15. NBA Prediction Markets & Live Odds 2026 — Polymarket
  16. UEFA Champions League markets — Polymarket
  17. Sports Odds & Prediction Markets 2026 — Polymarket
  18. State of Polymarket — Volume, Traders & Activity Stats — Polydata
  19. 100,000 Polymarket Accounts Booked Four-Figure Losses Since 2025, Bloomberg Finds — BeInCrypto
  20. Kalshi launches transparency features for 2026 midterm election markets — Kalshi
  21. Partnering with the Atlantic Council to measure the economic scale of major events — Kalshi
  22. KalshiEX LLC designation order, Nov. 3, 2020 — CFTC
  23. Industry Filings: Designated Contract Markets (DCM) — Polymarket US (QCX LLC) designated 07/09/2025 — CFTC
  24. Prediction market legal tracker — DeFi Rate (Third Circuit for Kalshi, April 6, 2026; Ninth Circuit against, Aug. 28, 2026; Sixth Circuit against, Sept. 25, 2026)
  25. New York sues Kalshi for alleged 'illegal gambling operation'

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