"What are prediction markets?"

"Prediction markets are exchanges where users trade binary event contracts that settle at $1 (yes) or $0 (no). Prices in cents represent the market's implied probability of an outcome. Unlike sportsbooks, prediction markets are peer-to-peer — every trade has a counterparty, not a house."

"What is the best prediction market platform?"

"Kalshi is the leading CFTC-regulated platform for US traders, with fiat settlement and a full API stack — and as of April 2026 it also hosts company KPI contracts via a Benzinga + Fiscal.ai partnership. Polymarket offers the broadest category coverage, blockchain-based settlement (pmUSD as of April 2026), and perpetual futures with 10x leverage. Robinhood embeds Kalshi event contracts directly in its brokerage app, and DraftKings Predictions (via Railbird) and FanDuel Predicts (via CME Group) serve sports-focused US users — neither yet offers a public developer API. Most serious agent builders connect to Kalshi and Polymarket; retail traders often start with Robinhood."

"Can I build a trading bot for prediction markets?"

"Yes. Kalshi offers REST v2, WebSocket, and FIX 4.4 APIs with a demo sandbox. Polymarket provides CLOB, Gamma, and Data APIs with the py-clob-client SDK. Both support automated order placement and position management."

"Are prediction markets legal in the US?"

"Kalshi operates under federal CFTC regulation in 40+ states but faces active legal challenges in several jurisdictions — an Ohio federal court ruled in March 2026 that Kalshi's sports contracts fall under state gambling law, followed by a $5M state fine on April 14, 2026. Polymarket acquired a CFTC license via QCEX and launched a US beta in January 2026; as of April 2026 access remains invite-only with broader public rollout expected in Q3–Q4 2026. The legal landscape is evolving rapidly."

"How do prediction market fees work?"

"Kalshi charges formula-based taker fees capped at $0.02 per contract, with lower maker fees. Polymarket operated fee-free for years; expanded taker fees went live March 30, 2026 with peak rates from 0.75% (sports) to 1.80% (crypto) and maker rebates of 20–50%. Fee structure directly impacts bot profitability."

Prediction Markets

Prediction markets are peer-to-peer exchanges where binary event contracts settle at $1 or $0, with prices representing implied probability. This hub covers every platform, API, bot, tool, and strategy guide on AgentBets related to prediction market trading — from Kalshi and Polymarket platform reviews to cross-market arbitrage algorithms.

What’s New (April 2026)

Polymarket pmUSD + CTF Exchange V2 — On April 6, 2026, Polymarket launched pmUSD (a 1:1 USDC-backed native stablecoin replacing bridged USDC.e) and began rolling out CTF Exchange V2 with EIP-1271 smart contract wallet support and faster order matching. V2 cutover completed April 22, 2026. See the Polymarket review.
Polymarket Perpetual Futures (April 21, 2026) — 10x+ leverage on crypto and stocks through the same CLOB API as binary markets.
Kalshi + Benzinga + Fiscal.ai KPI Markets (April 21, 2026) — company KPI event contracts tied to corporate performance (Tesla production, DoorDash deliveries, Netflix subscribers, earnings outcomes).
Ohio ruling (March 9, 2026) + $5M fine (April 14, 2026) — a federal court ruled Kalshi’s sports event contracts fall under state gambling law. State-by-state access continues to vary.

Platform Reviews

Kalshi Review: Platform, API & Agent Guide — CFTC-regulated exchange, $22B valuation, 350K+ markets, REST/WebSocket/FIX APIs, demo sandbox
Polymarket Review: Platform, API & Agent Guide — blockchain exchange on Polygon, $8B+ monthly volume, CLOB/Gamma/Data APIs, QCEX US relaunch, pmUSD settlement (April 6, 2026), CTF Exchange V2 with EIP-1271 smart wallet support, perpetual futures with 10x leverage (launched April 21, 2026)
FanDuel Predicts: Event Contracts Guide — FanDuel + CME Group joint venture, CFTC-regulated, all 50 states, no public API
DraftKings Predictions Guide for Agents — CFTC-regulated event contracts, Railbird Exchange, market-making, and agent integration strategies
Rain Protocol Guide: Decentralized PMs on Arbitrum — permissionless market creation, Delphi AI oracle, $RAIN tokenomics, OpenClaw agent SDK

Head-to-Head Comparisons

Kalshi vs Polymarket: Full Comparison — regulation, fees, APIs, liquidity, and bot compatibility
Polymarket vs Kalshi vs DraftKings — three-way comparison
Kalshi vs DraftKings Predictions
DraftKings vs Polymarket
Polymarket vs Kalshi for Bot Trading — API, pricing, and platform comparison for agents

Kalshi Guides

Kalshi API Tutorial — REST v2, WebSocket, FIX 4.4, RSA authentication, Python SDK
Kalshi Fees Guide — taker/maker fee formulas, deposit costs, fee-adjusted edge math
Kalshi Legal States Tracker — state-by-state status, court rulings, federal bills
Kalshi Sports Contracts Guide — moneylines, spreads, props, combos, odds conversion
How to Set Up a Trading Bot on Kalshi — step-by-step setup
Best Kalshi Trading Bots 2026 — top agents for the regulated market
How to Buy a Market-Making Bot for Kalshi
How to Rent a Copy-Trading Agent for Kalshi

Polymarket Guides

Polymarket API Tutorial — CLOB API, order placement, WebSocket streams
Polymarket US vs Global API — Ed25519 vs EIP-712, dual-stack agent pattern
Polymarket Rate Limits Guide — 429 errors, headers, retry strategies
Polymarket WebSocket & Orderbook Guide — channels, subscriptions, orderbook reconstruction
Polymarket Auth Troubleshooting — POLY headers, signatureType, funder
py_clob_client Reference — every Polymarket Python SDK method
Polymarket TypeScript SDK Reference
Polymarket Rust SDK Reference
Polymarket Gamma API Deep Dive — market discovery, price history, backtesting
Polymarket Subgraph Guide — on-chain data, GraphQL queries
How to Set Up a Trading Bot on Polymarket
Polymarket Trading Bot Quickstart
Polymarket + Coinbase Quickstart — agentic wallet integration
Best Polymarket Bots 2026 — every trading bot ranked
How to Buy an Arbitrage Bot for Polymarket
How to Rent a Sentiment Bot for Polymarket

Rain Guides

Rain Protocol Guide — AMM architecture, Delphi oracle, $RAIN token, agent SDK, OpenClaw integration
Rain Protocol Review — marketplace listing with builder economics and grant program

Cross-Platform API Reference

Prediction Market API Reference — unified reference across Kalshi, Polymarket, and DraftKings
Polymarket US vs Offshore API Comparison — four API ecosystems side-by-side
Unified API Comparison: Dome vs pmxt vs OddsPapi — abstraction layer trade-offs

Bot Rankings & Marketplace

Rankings:

Best Prediction Market Bots 2026 — complete rankings across all platforms
Best Prediction Market Arbitrage Bots
Best Open-Source Prediction Market Bots
Best Copy-Trading Agents

By Strategy (Kalshi):

By Strategy (Polymarket):

General:

Trading Bots by Sport

Tools

Kalshi API Tools
Kalshi News Bot — open-source AI trading bot
Polymarket CLI
Polymarket Agent Skills

Platform Directories

Kalshi Agent Directory — production agents integrated with Kalshi
Polymarket Bot Marketplace — active bots on Polymarket

Legal & Regulation

Is Kalshi Legal? State-by-State Tracker
Are Prediction Markets Legal? — US regulation, CFTC, election betting
KYC & Compliance for Agents

Math & Strategy

Prediction Market Math 101 — prices, probabilities, no-arbitrage condition
Expected Value for Prediction Market Agents
Kelly Criterion for Prediction Markets
Cross-Market Arbitrage — sportsbooks vs prediction markets
Prediction Market Microstructure — orderbooks, spreads, depth
Arbitrage Detection Algorithms
LMSR Automated Market Maker Math
Political Prediction Market Modeling
Prediction Market Scoring Rules

Terminology

Prediction Market Terminology — 80+ terms
Agent Betting Glossary — 130+ terms defined

Agent Frameworks

All Guides — 185+ technical guides
Comparisons & Rankings — odds, vig, and head-to-head comparisons
Agent Marketplace — buy, sell, rent trading agents
Betting Bots — bot reviews by sport and platform
Regulated Sportsbooks — DraftKings, FanDuel, Caesars, BetMGM