Predictefy Developers

APIs, SDKs, and WebSockets to build and execute across prediction markets.

[Predictefy @Predictefy]

Polymarket has 50% more crypto open interest, while Kalshi is generating 11.3x more notional volume.

We broke down the data across open interest, notional volume, and short-duration executed flow.

A deep dive into Kalshi vs Polymarket across crypto prediction markets. 🧵

[Predictefy @Predictefy]

Polymarket US has flipped Polymarket notional volume for the first time.

September Notional Volume:
1. Polymarket US - $2,994,169,131
2. Polymarket - $2,270,776,406

It comes as Polymarket ramps up efforts to scale its US business, with NFL season driving a new wave of sports-market activity.

Polymarket has also climbed to the top of the sports app download charts.

Source: https://t.co/aySg3156yj

[Predictefy Developers @predictefydevs]

A great place for polymarket and prediction market developers to get started.

100+ resources across 20 categories:
• AI trading agents and MCP servers
• Cross-venue aggregators
• Whale trackers
• Developer APIs

https://t.co/5X8rSa6YnG

[Marcus @marcustan1337]

I put together an open-source list of the best prediction market tools on GitHub.

It covers 100+ resources across 20 categories, including:

• AI trading agents and MCP servers
• Cross-venue arbitrage scanners and aggregators
• Whale trackers, wallet profilers, and alert bots
• Developer APIs, order book data, and infrastructure

Basically everything you need to build on prediction markets.

If you use or built a tool that isn't on the list, submit a pull request and I will add it in.

If you like the list, do give it a star! The link to the github is down below 👇

[Predictefy Developers @predictefydevs]

@marcustan1337 🔥🔥

[Predictefy @Predictefy]

$100 on Chelsea to beat Arsenal.

Payouts on prediction markets vs sportsbooks:
1. @SX_Bet - $533
2. @predofficial - $526
3. @bet_105 - $517
4. @Novig - $513
5. @ProphetX - $512
6. @Polymarket - $505
7. @FanDuel - $500
8. @Kalshi - $496
9. @predictdotfun - $490
10. @Duelbits - $490
11. @DraftKings - $490
12. @Stake - $490
13. @trylimitless - $477
14. @Bet365 - $475
15. @Betfair - $471

Prediction markets currently offer some of the strongest Chelsea moneyline payouts, with SX Bet leading at $533.

Among sportsbooks, Duel Bits offers the highest payout at $500.

[Predictefy @Predictefy]

Kalshi dominated August prediction market notional volume, doing 3.6x more volume than the other 10 platforms combined.

August Notional Volume:
1. @Kalshi - $40.03B
2. @Polymarket - $4.59B
3. @Polymarket (US) - $3.83B
4. @cryptocom -$968.18M
5. @opinionlabsxyz - $739.75M
6. @RotheraMarkets - $524.26M
7. @predictdotfun - $417.47M
8. @trylimitless - $96.24M
9. @SX_Bet - $59.82M
10. @Predictstreet - $35.69M
11. @HyperliquidX - $11.54M

Across 11 tracked venues, August notional volume reached $51.30B.

Polymarket and Polymarket US combined for $8.42B. The US venue contributed 45.5% of that total and reached 83.5% of the main platform’s volume.

The top three venues accounted for 94.4% of all tracked activity, leaving just $2.85B for the remaining eight platforms.

Cryptocom, Opinion, Rothera and Predict Fun, formed the middle tier, combining for $2.65B.

The remaining venues generated $203.29M combined, less than 0.4% of total tracked volume.

[Predictefy @Predictefy]

New GTA 6 Arbitrage Opportunity

Will the GTA 6 extended look be at least 30m:
1. YES on Polymarket: 8¢
2. NO on Kalshi: 74¢

Resolves in less than 48 hours.

[Predictefy @Predictefy]

Prediction market notional volume surged during the World Cup, and average weekly volume is still 50.1% higher than before the tournament began.

Pre vs. Post-World Cup Notional Volume:
1, @HyperliquidX +328.4%
2, @Kalshi +96.1%
3, @Polymarket (US) +87.2%
4. @opinionlabsxyz +17.0%
5. @MyriadMarkets -10.6%
6. @Polymarket -46.2%
7. @predictdotfun -63.2%
8. @trylimitless -88.9%

Hyperliquid recorded the largest post-World Cup expansion, with average weekly notional volume up 328.4% from its pre-tournament baseline.

Across leading venues, average weekly notional volume rose from $7.03B pre-World Cup to a peak of $16.03B during the tournament, and remains at $10.55B post-World Cup.

The World Cup spike has cooled, but prediction market activity has not returned to its previous baseline.

Behind Hyperliquid, Kalshi and Polymarket US retained the strongest gains, up 96.1% and 87.2% respectively.

The World Cup wasn’t just a temporary volume spike.

It appears to have left prediction markets operating at a materially higher level than before.

To measure the World Cup effect, we compared average weekly notional volume across leading venues in the month before kickoff with the averages during and after the tournament.

[Predictefy @Predictefy]

Leading prediction markets generated $110.35 billion in notional volume in Q2 2026, marking a 44.8% increase from Q1.

QoQ Notional Volume Growth:
1. @Polymarket (US) +463.3%
2. @trylimitless +252.9%
3. @Kalshi +102.8%
4. @predictdotfun +89.4%
5. @gemini +86.1%
6. @SX_Bet +43.3%
7. @Polymarket +2.3%
8. @cryptocom -32.4%
9. @opinionlabsxyz -80.7%
10. @MyriadMarkets -93.8%

Polymarket US, the CFTC-regulated arm of Polymarket, led the market in Q2 with 463.3% quarter-over-quarter growth.

Limitless followed with 252.9% growth, reinforcing its position as one of the fastest-expanding prediction market venues.

PredictDotFun and Gemini remained closely matched, each recording approximately 86%–89% QoQ growth.

At the other end of the market, BSC-based venues Opinion and Myriad experienced sharp contractions, declining 80.7% and 93.8%, respectively, alongside a meaningful loss of market share.

[Predictefy @Predictefy]

$100 on England to beat Argentina in the World Cup.

Payouts on prediction markets vs sportsbooks:
1. @predofficial - $284
2. @Novig - $282
3. @SX_Bet - $281
4. @Duelbits - $280
5. @bet_105 - $278
6. @trylimitless - $276
7. @ProphetX - $278
8. @Betfair - $277
9. @Fanatics - $275
10. @Polymarket - $273
11. @Bet365 - $270
12. @DraftKings - $275
13. @Stake - $270
14. @Kalshi - $266
15. @Underdog - $263

Prediction markets currently offer the best France moneyline odds, led by Pred. Among sportsbooks, Duel Bits and Bet105 lead the list.

Payouts shown for prediction markets and sportsbooks exclude fees and transaction costs.

[Predictefy @Predictefy]

$100 on France to beat Spain in the World Cup.

Payouts on prediction markets vs sportsbooks:
1. @predofficial - $253
2. @Novig - $253
3. @SX_Bet - $252
4. @trylimitless - $251
5. @bet_105 - $251
6. @ProphetX - $247
7. @Polymarket - $245
8. @Bet365 - $245
9. @DraftKings - $240
10. @Stake - $238
11. @Kalshi - $234

Prediction markets currently offer the best France moneyline odds, led by Novig and Pred. Among sportsbooks, Bet105 leads the list.

Payouts shown for prediction markets and sportsbooks exclude fees and transaction costs.

[Predictefy Developers @predictefydevs]

@Predictefy 3-1 PSG

[Predictefy Developers @predictefydevs]

@Predictefy Sports!

[Predictefy Developers @predictefydevs]

@Predictefy United are cooked!

[Predictefy Developers @predictefydevs]

@Predictefy 4-1 Liverpool

[Predictefy Developers @predictefydevs]

@Predictefy 6-9

[Predictefy Developers @predictefydevs]

@Predictefy crazyyyy

[Predictefy Developers @predictefydevs]

@Predictefy Arsenal about to bottle another one tomorrow

[Predictefy Developers @predictefydevs]

@Predictefy what's this all about then