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What this page covers

  • What happened to PredictIt
  • Active prediction market platforms in 2026
  • Feature comparison: Kalshi, Polymarket, Robinhood
  • API access and programmatic trading on each platform
  • How to build on top of modern prediction market APIs

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What happened to PredictIt

PredictIt operated under a CFTC no-action letter that allowed it to offer binary political prediction markets. In 2022, the CFTC withdrew that letter, ordering PredictIt to wind down operations. The platform stopped accepting new markets and began closing existing ones. PredictIt’s winding down left a gap for political and event prediction markets — but several platforms have since filled and expanded that space.

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Active platforms in 2026

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Kalshi

Kalshi is the first CFTC-regulated prediction market exchange in the United States. It operates as a designated contract market (DCM), giving it a permanent regulatory framework rather than a temporary no-action letter.
FeatureDetails
RegulationCFTC-regulated DCM
MarketsEconomics, politics, crypto, weather, entertainment, sports
CurrencyUSD (ACH/wire deposits)
APIFull REST API at trading-api.kalshi.com
AuthRSA-PSS signed headers
Python SDKkalshi-python (community)
FeesMaker: free. Taker: 0.07 × price × (1-price)
Programmatic tradingYes, encouraged
Kalshi covers far more categories than PredictIt ever did — beyond politics, it offers markets on Fed rate decisions, inflation data, temperature records, box office results, and cryptocurrency prices.

Kalshi API guide

Full developer guide: authentication, endpoints, market data, and code examples.

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Polymarket

Polymarket is the largest prediction market by volume globally. It is crypto-native, built on Polygon, and uses USDC for settlement.
FeatureDetails
RegulationNot CFTC-regulated (offshore)
MarketsPolitics, crypto, AI, science, sports, entertainment
CurrencyUSDC on Polygon
APIGamma Markets API (read) + CLOB API (trade)
AuthHMAC-SHA256 signed requests
Python SDKpy-clob-client (official)
FeesLow maker/taker fees
Programmatic tradingYes, via CLOB API
Polymarket has the deepest liquidity and broadest market coverage. It attracts a global, crypto-native audience.

Polymarket API guide

Full developer guide: CLOB, Gamma API, py-clob-client, condition IDs, and code examples.

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Robinhood

Robinhood added event contracts (prediction markets) to its existing brokerage platform, bringing prediction markets to a mainstream retail audience.
FeatureDetails
RegulationSEC/FINRA-regulated brokerage
MarketsPolitics, economics, select events
CurrencyUSD (existing Robinhood account)
APILimited public API for event data
Programmatic tradingLimited
Robinhood’s prediction markets are accessible to anyone with a Robinhood account, but the API surface for programmatic trading is more limited than Kalshi or Polymarket.

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Comparison: PredictIt vs modern platforms

FeaturePredictIt (legacy)KalshiPolymarketRobinhood
StatusWinding downActiveActiveActive
RegulationCFTC no-action (withdrawn)CFTC DCMNone (offshore)SEC/FINRA
CategoriesPolitics only10+ categories10+ categoriesSelect events
Max position$850No capNo capVaries
API accessRead-onlyFull RESTFull REST + CLOBLimited
Programmatic tradingNoYesYesLimited
SettlementUSDUSDUSDCUSD

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Key improvements over PredictIt

  • No $850 position limit: Kalshi and Polymarket allow unlimited position sizes
  • More categories: Economics, crypto, weather, entertainment — not just politics
  • Real APIs: Full REST APIs with order placement, position management, and streaming
  • Lower fees: Kalshi maker orders are free; Polymarket has competitive fees
  • Faster settlement: Markets resolve and pay out within hours, not days

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Building on modern prediction market APIs

If you previously built tools for PredictIt, the modern ecosystem is much more developer-friendly: 
import httpx

# Unified access to Kalshi + Polymarket + Robinhood via Rekko
client = httpx.Client(
    base_url="https://api.rekko.ai/v1",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
)

# List markets across all platforms
markets = client.get("/markets", params={"limit": 10}).json()
for m in markets:
    print(f"{m['platform']:12} | {m['title'][:50]:50} | YES: {m['yes_price']:.2f}")
Rekko provides a unified API layer that normalizes data across all three platforms, adds AI-powered analysis, and provides trading signals — capabilities that were never available with PredictIt.

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What’s next

API comparison

Detailed comparison of Kalshi, Polymarket, and Robinhood APIs.

Build a trading bot

Step-by-step tutorial for a Python trading bot.

Quickstart

Get a free API key and make your first call.