Live Kalshi + Polymarket data

Practice on live markets. Risk nothing.

Trying to make money on prediction markets? Test every trade first. Prove your edge on live Kalshi and Polymarket order books—with paper money, realistic fees, and zero capital at risk.

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Explore live markets
Free to startNo card$1,000 paper balance
Live market workspace Synced
kalshiView market ↗

Chicago C wins by over 3.5 runs?

YES25¢NO77¢BOOK DEPTH12 levels
Paper moneyReal order booksVenue fees included
Live data from
Supported venues
Kalshi
Polymarket
Your funds never leave your wallet.
Live markets
Chicago C wins by over 3.5 runs?Yes 25¢No 77¢$3K volWill the U.S. invade Iran before 2027?Yes 14¢No 86¢$64.8M volCarlos Rodón: 15+ Outs Recorded?Yes 62¢No 41¢$2K volWill Gavin Newsom win the 2028 Democratic presidential nomination?Yes 14¢No 86¢$27.1M volChicago C wins by over 2.5 runs?Yes 33¢No 69¢$2K volWill the Iranian regime fall before 2027?Yes 8¢No 93¢$25.6M volOver 8.5 runs scoredYes 47¢No 53¢$1K volWill there be no change in Fed interest rates after the September 2026 meeting?Yes 49¢No 52¢$22.9M volChicago C wins by over 1.5 runs?Yes 42¢No 59¢$1K volPutin out as President of Russia by December 31, 2026?Yes 7¢No 94¢$20.0M volSalvador Perez: 1+ home runs?Yes 16¢No 85¢$1K volWill the Fed increase interest rates by 25 bps after the September 2026 meeting?Yes 51¢No 50¢$18.3M volCarter Jensen: 1+ home runs?Yes 19¢No 83¢$790 volWill Gavin Newsom win the 2028 US Presidential Election?Yes 7¢No 93¢$18.1M volOver 7.5 runs scoredYes 56¢No 45¢$588 volAnthony Molina: 15+ Outs Recorded?Yes 47¢No 54¢$525 volMariusz Zwolinski winsYes 47¢No 78¢$442 volBobby Witt Jr.: 1+ home runs?Yes 17¢No 84¢$402 volOver 2.5 runs scoredYes 93¢No 5¢$182 volBo Bichette: 3+ hits?Yes 7¢No 94¢$161 volJac Caglianone: 2+ total bases?Yes 49¢No 53¢$102 volFirst 5 innings: Over 4.5 runsYes 47¢No 57¢$101 volCarter Jensen: 1+ hits + runs + RBIs?Yes 73¢No 28¢$75 volWill the temp in Los Angeles be above 68.99° on Sep 5, 2026 at 4am EDT?Yes 64¢No 44¢$55 volCarson Benge: 3+ hits?Yes 5¢No 96¢$51 volGeorge Springer: 1+ RBIs?Yes 40¢No 62¢$51 volVladimir Guerrero Jr.: 2+ total bases?Yes 49¢No 55¢$51 volGeorge Springer: 2+ total bases?Yes 46¢No 56¢$51 vol
How it works

Turn a market opinion
into tested evidence.

Making money takes more than being right. Use the dashboard or API to find out whether your trade still works after live liquidity, slippage, and fees.

01

Find your market

Search active Kalshi and Polymarket events in one fast, unified feed.

02

Place the trade

Trade manually or by API with market, limit, stop, and bracket orders.

03

Measure the edge

See fees, VWAP, slippage, positions, and P&L in one honest record.

Execution that tells the truth

A midpoint is a quote.
A fill is a journey.

PredArena walks the live book level by level. You see whether the edge survives thin liquidity, price impact, and venue-specific fees.

See exactly how simulation works →
LIVE ASK BOOKQUANTITYCOST
54¢80$43.20
53¢120$63.60your order
52¢45$23.40
Naive quote52.0¢
Your real VWAP53.1¢
Impact caught+1.1¢
One arena, two ways in

Trade with instinct.
Or ship the system.

A focused interface for curious traders, plus infrastructure for serious automation.

For manual traders

See the market.
Make the call.

Watchlists, quick order tickets, position tracking, and transparent performance—without real capital on the line.

Start trading →
For bots & agents

Test the logic.
Prove the edge.

Production-shaped orders, idempotency, webhooks, rich analytics, and isolated portfolios for every strategy.

Read the API docs →
POST /api/v2/portfolio/orders
{
  "ticker": "KXRT-CRI-90",
  "action": "buy",
  "yes_no": "yes",
  "count": 10
}
Simple pricing

Start free.
Scale when it works.

Every plan includes live market data, realistic paper fills, and a full performance record.

Free

$0/ forever

Learn the product and test a first strategy.

  • 1 portfolio
  • $1,000 paper balance
  • 1,000 orders / month
Start free
Most popular
Starter

$9/ month

For active traders and early automation.

  • 1 portfolio
  • $10,000 paper balance
  • 25,000 orders / month
Choose Starter
Pro

$49/ month

Run multiple strategies at serious volume.

  • 5 portfolios
  • $100,000 paper balance
  • 250,000 orders / month
Choose Pro
Good questions

Know what you’re trading.

PredArena is intentionally clear about what is real, what is simulated, and where they differ.

Is any real money at risk?+

No. PredArena never routes real-money orders. You trade with paper balances against simulations derived from live public venue data.

Are fills just based on the midpoint?+

No. Market orders walk displayed order-book depth to calculate VWAP and price impact, then apply the venue’s modeled fee schedule.

Can I connect an existing bot?+

Yes. Create a portfolio-scoped API key and route supported order requests to the PredArena REST API. The docs include examples and exact differences from live venues.

Which venues are supported?+

Kalshi and Polymarket are supported for live market discovery, order-book-based simulated fills, and venue-aware fee modeling.

Ready when you are

Make your mistakes
beautifully free.

Open a portfolio in seconds. No credit card, no real-money orders, no expensive surprises.

Start paper trading →