Prediction Almanac

Every prediction market worth trading, the data you can actually backtest on, and the tools people have really shipped. Rebuilt from scratch daily, so it can't rot.

Now a browsable page too: kacho.io/wiki/prediction-markets-directory. It renders straight from this repo and rebuilds daily, so anything accepted here shows up there as well, automatically. One submission, both places.

Platforms · Data sources · Tools · Research · Blogs & X · Paid · Contributing · How it works

Most awesome lists are a photo of what somebody found interesting one afternoon two years ago. The links rot and nobody notices.

This one measures itself. Volume comes from an API, repo health from GitHub, a blog's last post from its own feed. Nothing here is a number I typed once and left to age. Where a cell is blank it's because no free source exists, and the entry tells you what I looked for.

Every entry is a YAML file in data/. This page is built from them, so don't edit it, the build will overwrite you. Link-rot sweeps and the submission bot are still to come (roadmap).

I built this and I maintain it, which means it carries my blind spots. If something is missing, wrong, or has quietly died, open an issue. That's the only way a list like this stays correct.

Platforms

On-chain markets

Platform	Type	Since	Volume	Who can trade	Description
Polymarket	CLOB, Polygon	2020	$2.7B/30d	🌍 exc. 🇺🇸🇬🇧🇨🇦🇦🇺 +39	Largest on-chain prediction market; USDC-settled CLOB on Polygon.
predict.fun	CLOB, Blast	2024	$410.1M/30d	🌍 exc. 🇺🇸🇬🇧🇦🇺🇫🇷 +9	Polymarket-style on-chain CLOB prediction market on Blast.
Opinion	CLOB, BNB Chain	2025	$219.4M/30d	🌍 exc. 🇺🇸🇬🇧🇫🇷🇨🇳 +10	CLOB on BNB Chain, YZi Labs backed, covering macro, crypto and sports. Volume ranks near the top but its points programme pays on trade size, so treat the figure as contested.
SX Bet	CLOB, SX Rollup	2019	$47.9M/30d	🌍 exc. 🇺🇸🇬🇧🇦🇺🇩🇪 +19	Peer-to-peer betting exchange with a genuine order book on its own Arbitrum Orbit L2; no house or vig, but every currently active market is sports.
Limitless	CLOB, Base	2024	$599.8k/30d	🌍 exc. 🇺🇸🇧🇾🇨🇺🇮🇷🇰🇵🇷🇺🇸🇾	Fast-cycle (hourly/daily/weekly) prediction markets on Base, aimed at traders.
Myriad	CLOB, BNB Chain +3	2025	$165.4k/30d	🌍 exc. 🇺🇸🇫🇷🇸🇬🇧🇸 +14	Prediction market from Dastan (Decrypt, Rug Radio): an off-chain-matched, on-chain-settled order book on BNB Chain, plus AMM markets on Abstract, Celo, and Linea.

Regulated exchanges & brokers

Platform	Type	Since	Volume	Who can trade	Description
Kalshi	Regulated exchange	2021	$17.8B/30d	🌍 exc. 🇬🇧🇨🇦🇦🇺🇫🇷 +51	CFTC-regulated US event-contract exchange spanning politics, economics, weather, and sports.
Gemini Predictions	Regulated exchange	2025	$42M/30d	only 🇺🇸	CFTC-regulated event contracts from Gemini's own DCM affiliate; yes/no and categorical markets on a central limit order book, settled in USD.
Betfair Exchange	Regulated exchange	2000	-	🌍 exc. an undisclosed list	The largest betting exchange; politics and current-affairs markets alongside sports.
IBKR Prediction Markets	Broker → ForecastEx, Kalshi, CME	2024	-	only 🇺🇸🇨🇦🇸🇬🇭🇰	Interactive Brokers' front-end for binary event contracts, routing to its wholly-owned ForecastEx plus Kalshi and CME; the EEA offering is ForecastEx-only and professional-clients-only.
PredictIt	Regulated exchange	2014	-	only 🇺🇸	Long-running US political research market; capped stakes and a small contract universe.
Robinhood Prediction Markets	Broker → Kalshi, ForecastEx, Rothera	2024	-	only 30 countries	Robinhood Derivatives, a CFTC-registered FCM, sells binary event contracts in-app and routes the orders to the Kalshi, ForecastEx, and Rothera exchanges.
Smarkets	Regulated exchange	2008	-	🌍 exc. 🇺🇸🇦🇺🇫🇷🇳🇱 +15	UK-licensed betting exchange with notably deep political markets.

Research & play-money venues

You can't make real money on these. What you can get is complete, free history, and that's what you backtest on before risking anything on the venues above.

Platform	Type	Since	Who can trade	Description
Headline Arena	Forecasting	2026	🌍 everyone	Forecasting arena where AI agents submit probabilistic calls on macro, price and event challenges that settle mechanically, scored by Brier and calibration.
Manifold	Play-money	2021	🌍 everyone	Play-money markets anyone can create; the most open API and data of any platform.
Metaculus	Forecasting	2015	🌍 everyone	Long-horizon forecasting community with tournaments and track records; aggregates probabilistic forecasts rather than trading.

"Who can trade" comes straight out of each platform's own terms. It's a fact about their rules, not advice, and definitely not a workaround. Hover a cell to see the countries by name, click it for the document I read them from. 🌐 permissionless means the protocol enforces nothing, though the official front end may still block you.

Volume is notional USD over the period shown. A blank means nobody publishes a free comparable figure, and the entry says what turned up instead. Some venues disclose only commission revenue or a contract count. Neither of those is volume.

Don't add the column up. Brokers route their flow into exchanges sitting in the same table, so you'd count it twice. Dead venues keep their file in data/ but drop off the page.

Considered and left out, with the reason

Resource	Why not
Azuro	Sports-betting liquidity protocol powering third-party sportsbooks, not a prediction market venue in its own right.
Overtime	Sports betting (Thales protocol family) with an AMM, not event-outcome prediction markets.
Hyperliquid Outcomes (HIP-4)	Exchange infrastructure rather than a venue in its own right - HIP-4 is an order-book primitive that front-ends build on, and mainnet inventory is a handful of recurring crypto price binaries.
ForecastEx	A CFTC-licensed exchange that retail cannot access directly; it is the matching venue behind broker front-ends such as IBKR ForecastTrader, which are listed instead.
Iowa Electronic Markets	Academic research market with $500 account caps, no API, and negligible volume; of historical interest rather than practical use.
Futuur	Play-money side adds no data or liquidity, and the real-money side is offshore-licensed with 39 countries blocked and no historical API. Nothing in the directory references it.
Hypermind	Prize-based forecasting with no public API and no exportable data, so it offers nothing to a trader or a builder.
Good Judgment Open	No API and no data export. Metaculus covers the same ground with full public forecast history.
Rain	A real venue, but not a measurable one. DefiLlama tracks its retired deployment and reads zero, its own API reports pool collateral rather than traded volume, and roughly half the all-time volume was one address trading with itself.

Think one of these belongs? Open an issue. The reasons live in data/excluded.yml and changing my mind is a one-line edit.

Data sources

Beyond a venue you need history to test a strategy on and a feed to price against. That's it.

Platform APIs aren't here. Every venue has one for its own book and you'll find it in their docs in about thirty seconds, so a row saying "this exchange has an exchange API" would only push the useful entries further down the page.

Datasets

History you can backtest on.

Dataset	Covers	Format · granularity	Coverage	Known gaps
Kalshi trades (TrevorJS)	kalshi	parquet · trades + market metadata with outcomes	2021-06-2026-01 (full)	Stops January 2026 and has not been updated since. No order book.
pdata	polymarket, kalshi, manifold, myriad, limitless, opinion	-	- (unknown)	-
pmxt archive	polymarket, kalshi, limitless, opinion	parquet · hourly order-book snapshots	2026-present (partial)	Per-venue start dates differ - Polymarket from February 2026, Kalshi, Limitless and Opinion from May. Polymarket splits into v1 and v2 across the CLOB migration.
Polymarket aligned tape (TimeSeventeen)	polymarket	parquet · trades with resolution, fees and event-normalised probability	2022-11-2026-04, v2 continues to date (full)	Needs the companion v2 repo for coverage past the April 2026 migration. Do not pool binary, up-down and NegRisk markets without checking category.
Polymarket L2 depth (vpcapitano)	polymarket	parquet · 10-level book depth, spread, best bid/ask	2025-10-2026-03 (partial)	Six months only, and no resolution column - join outcomes yourself.
prediction-market-analysis	polymarket, kalshi	compressed bulk dataset (~36GB) · trade	through 2025 (partial)	A research framework as much as a dataset - it ships indexers for collecting new data, so freshness depends on running them yourself.

Odds & reference feeds

What you price against. Work out your own number, then go and see where the market has it.

Feed	Prices	Format · granularity	Coverage	Known gaps
Betfair Exchange	Sports and politics	JSON-RPC / REST · prices and market book; historical as market ticks	live, plus a separate historical archive (partial)	Needs an account and app key. The free Delayed key omits traded volume, and the GBP 499 Live key forbids read-only data collection. History is a separate paid product at historicdata.betfair.com, with politics coverage thinner than sports.
ElectionBettingOdds	Elections	HTML (no API) · per-market odds and cumulative matched USD, by venue	election markets only (partial)	Scraped from the page, with no API and no time series - figures are cumulative per market rather than per period, and only election markets are covered.
Live Tennis API	Tennis	JSON REST / WebSocket / MCP · live match state per point, plus fixtures, H2H and rankings	live + 1968-2022 results archive (partial)	Free tier is keyed and capped at 30 req/min and 100/day, and covers live scores, players, fixtures and usage only. Completed-match history needs a paid plan, and the WebSocket feed plus model win probability sit on the top tier.
Open-Meteo	Weather	JSON REST · hourly forecast, ensemble members, historical reanalysis	1940-present, plus forecasts (full)	Non-commercial use is free without a key; commercial use needs a paid plan. Ensembles are raw members, so you compute the probability yourself.
Oracle Markets	-	-	- (unknown)	-
Pinnacle API	Sports	JSON REST · pre-match and live odds, lines, limits	live only (partial)	Account credentials required, and no history - Pinnacle is a sharp sportsbook, so this is a pricing benchmark rather than a dataset.
The Odds API	Sports	JSON REST · odds by bookmaker, per market	live + limited history (partial)	The free tier is request-capped and keyed; historical odds sit behind a paid plan, and bookmaker coverage varies by region.

This list is short on purpose. A directory that lists everything is as useless as one that lists nothing. But a short list is one person's taste, so if you price against something that isn't here, suggest it.

Tools

Trading bots, agents & execution

Code that trades: market makers, arbitrage bots, agents, and the layers you execute through. Read the licence and the code before you point any of it at real money. None of it is audited and a stale repo is a liability.

Tool	Covers	Status	Description
CCXT	polymarket, kalshi, limitless, myriad	44,847★ · 2026-11-10	The long-established unified trading library, which now lists Polymarket, Kalshi, Limitless and Myriad alongside 100+ crypto exchanges across seven languages.
CloddsBot	polymarket, kalshi, manifold, metaculus, predict-fun	3,092★ · 2026-11-06	Self-hosted autonomous agent spanning prediction markets, perps and DEXs, with Kelly sizing, VaR and CVaR limits and circuit breakers.
PMXT SDK	polymarket, kalshi, limitless, myriad, metaculus, gemini-predictions	2,208★ · 2026-09-30	CCXT-style unified API across 14+ prediction markets, with Python and TypeScript SDKs, a CLI, and MCP integration - one integration instead of fourteen.
poly-maker	polymarket	1,527★ · 2026-07-09	Maker-only market making on Polymarket CLOB V2: depth-weighted microprice fair value, inventory skew, volatility-widened spreads and a regime state machine.
kalshi-ai-trading-bot	kalshi	652★ · 2026-11-09	Kalshi strategy toolkit with authenticated client, position tracking, paper mode and example strategies whose losing periods the README documents.
oracle3	kalshi, polymarket	568★ · 2026-10-12	Prices baskets of related event contracts against five no-arbitrage relations at executable prices net of each venue's fees, then trades them live or on paper under pre-trade risk limits.
KalshiMarketMaker	kalshi	467★ · 2026-04-14	Avellaneda-Stoikov market making on Kalshi - reservation price, asymmetric quotes and inventory-risk-adjusted sizing, with portfolio caps and Docker deployment.
Kalshi Trading Bot CLI	kalshi	416★ · 2026-10-01	CLI that researches a question, forms an independent probability, computes edge against the live book and sizes with Kelly - with a demo mode.
PolyClaw	polymarket	360★ · 2026-04-28	Polymarket agent skill that browses markets and executes on-chain via split plus CLOB, showing the mint path rather than naive taking.
Homerun	polymarket, kalshi	220★ · 2026-10-27	Write Python strategies, backtest them on L2 book replay with Cox hazard fill modelling, then run the same code in shadow or live mode.
Polymarket Alpha Bot	polymarket	184★ · 2026-08-05	Finds covering portfolios across logically related markets by extracting implications, validating them, then pricing the trade on live quotes.
polymm	polymarket	121★ · 2026-08-16	Sports market-making and arbitrage bot for Polymarket: de-vigs sportsbook odds, quotes both sides, and hedges the fills.
Olas Predict trader	polymarket, omen	86★ · 2026-11-10	Autonomous trading agent shipped as an on-chain Olas service, with separate strategies for Polymarket on Polygon and Omen on Gnosis.
prediction-market-agent-tooling	polymarket, manifold, omen	65★ · 2026-04-22	Gnosis toolkit for building AI agents that trade on prediction markets.
Garnet	polymarket	4★ · 2026-10-02	Self-hosted Polymarket copy-trading engine in Rust: mirrors wallets you pick, detects their fills three ways, with shadow mode at real fees and per-event caps. BUSL, free for individuals only.

Cross-venue search & arbitrage

Finding where an event trades, and where it trades cheaper. Most of the edge in this space lives in that gap.

Tool	Covers	Access	Description
Prediction Market News	polymarket, kalshi	free	Cross-venue screener over 10,752 matched Polymarket and Kalshi markets, showing consensus odds, per-venue spread, open interest, depth and resolution rules.
Predicts.guru	polymarket, kalshi, limitless	free	No-login wallet checker, smart-money radar and live trade feed, plus an arbitrage scanner matching Polymarket against Kalshi and Limitless.
Chironus Scanner	polymarket, kalshi	freemium	Scanner across all live Polymarket and Kalshi markets with category, volume, price-band and time-to-close filters; free tier serves delayed prices.
Adjacent News	polymarket, kalshi, manifold, metaculus	free	News and research terminal built around prediction-market data, with a market-data API.

Dashboards & market data

Watching flow, positions and volume without building your own pipeline. The leaderboards also tell you which wallets are worth copying, or fading.

Tool	Covers	Access	Description
Dune: Kalshi Overview	kalshi	free	Dedicated Kalshi dashboard covering exchange volume, trade counts and activity trends, without a research-platform subscription.
Dune: Prediction Markets	polymarket, kalshi, limitless, myriad, predict-fun	free	Multi-venue on-chain dashboard covering weekly volume, trade counts, open interest and unique users across seven venues - the broadest free venue-share view.
OVERROUND	polymarket	freemium	Skill-adjusted leaderboard scoring resolved on-chain positions against the price paid, de-correlating events and shrinking small samples so sharp money is defensible.
PMWallets	polymarket	freemium	Polymarket leaderboard from the Polygon ledger: linked wallets scored as one trader, 95% CI win rates, profit without the best market. Free board; addresses unlock at $0.50-$1 each.
Polyguana	polymarket	free	Live rankings across 157k Polymarket markets with 24h movers, a category heatmap, watchlist alerts and a resolved-market archive.
Polysights	polymarket	freemium	Polymarket analytics suite: market screener, trader and portfolio analytics, a sharp-wallet scanner, and API, MCP and CLI access.
PolyTracer	polymarket	free	Polymarket wallet analyzer: paste any address and it replays every fill from Polygon chain data, recomputing win rate, ROI and P&L, with per-category breakdowns and a live whale feed.
Resolve Markets	polymarket, kalshi, predict-fun, predictit, manifold	freemium	Multi-venue suite with separate Kalshi, Polymarket and predict.fun dashboards, whale watch, contract comparison and a purpose-built negative-risk tool.

Data tooling

For getting, replaying and cleaning market data yourself. Anything you can only use by paying sits under Paid services instead.

Tool	Covers	Access	Description
Marketlens	polymarket	freemium	Tick-level Polymarket book history from March 2026 across the whole catalog, not just crypto, with a backtester that models queue position, latency and slippage. Free tier, then $39/mo.

Research

Mostly papers, and that isn't an accident. Every venue's "learn" page is marketing. The 2026 academic work is free and genuinely useful: order-book microstructure, maker versus taker returns, where prices are systematically wrong, and how much arbitrage capacity really exists.

Paper	Covers	Year	Description
Arbitrage Analysis in Polymarket NBA Markets	polymarket	2026	75M book snapshots over 173 NBA games: only 7 executable single-market arbs with a median 3.6s life, and combinatorial episodes mostly capped near 15 shares.
Decomposing Crowd Wisdom: Domain-Specific Calibration Dynamics	kalshi, polymarket	2026	353M trades across 429k Kalshi and Polymarket contracts, mapping where prices are systematically wrong - political markets stay compressed toward 50%.
Logarithmic Market Scoring Rules	general	2002	Hanson's LMSR - a scoring rule doubling as a bounded-loss automated market maker, and the pricing engine behind most subsidised event markets.
Makers and Takers: The Economics of the Kalshi Prediction Market	kalshi	2026	Transaction-level study of 300k+ Kalshi contracts: a strong favorite-longshot bias after fees, and higher realised returns for makers than for takers.
Optimal Market Making in Prediction Markets	general	2026	Derives optimal bid and ask quotes for binary event contracts via an HJB equation, handling inventory and terminal settlement risk - the binary analogue of Avellaneda-Stoikov.
Prices, Probabilities, and Parlays: Systematic Bias in Sports Prediction Markets	kalshi	2026	23M Kalshi moneyline trades: calibration holds mid-contract but breaks in the final ten minutes, and cross-game parlays are overpriced relative to their legs.
The Anatomy of a Decentralized Prediction Market	polymarket	2026	Microstructure of 30bn Polymarket book events - longshot spread premium, ~1% wash trading, and a warning that trade direction inferred from the public book is only ~59% accurate.

Blogs & X accounts

Blogs

People worth reading, free and not owned by an exchange. Last post comes from each blog's own feed, so one that goes quiet shows it here instead of sitting around looking current. Building something in this space? Put yourself in this table.

Blog	Last post	Description
Alphanume Research	2026-11-05	Free quant-flavoured writing on actually trading these venues - order-book mechanics, bonding bots, and how platform rule changes hit short-dated markets.
Imperfect Information	2026-08-06	Rajiv Sethi on prediction-market accuracy, wash trading and market design - the most rigorous writing on when prices beat polls and where they fail.
Kacho	2026-08-13	Data engineer building side projects in public, including the Polymarket market-making bot polymm, and posting the verified metrics behind them.
Sentinel Global Risks Watch	2026-11-09	Free weekly global-risk roundup written with elite forecasters, tracking the geopolitical situations that Kalshi and Polymarket list as contracts.
The Event Horizon	2026-08-12	Dustin Gouker's near-daily free trade publication on volume shifts, contract design, exchange litigation and CFTC/state regulation - the structural risk that moves liquidity.

X accounts

The only rows here that nothing checks. X killed its free API tier in February 2026, so confirming an account is even still alive now costs money per lookup. These three are in on outside coverage, not follower counts. I checked the podcasts too. None of them qualified.

Account	Description
Domer (@Domahhhh)	Polymarket's number one all-time trader by volume and profit, around $300M across 5,000+ markets, and the most-cited independent voice in the space.
Esoteric Catboy (@catboyautist)	Trader who posts positions and reasoning openly, particularly on Kalshi mention markets; quoted in Bloomberg's 2026 prediction-markets feature.
Kyle (@KyleDeWriter)	Tracks the Polymarket leaderboard and explains platform mechanics, such as what removing the 500ms order delay did to short-dated markets.

Paid services

These cost money, and they're here because each one publishes its price and lets you check the data before paying: a sample file, a trial, a public endpoint. That free part is what got checked, not the paid tier. Read the terms before you build on any of them.

Service	What	Covers	Price	Check it free	Description
outcometick	Dataset	polymarket, predict-fun	from $10/mo per venue, $18/mo both	sample	Tick-level Polymarket and Predict.fun crypto Up/Down history since June 2026, with the Chainlink settlement feeds, strikes and outcomes needed to recompute each settlement.
Probalytics	Data tooling	polymarket, kalshi	from $39/mo, 3-day trial	sample	Millisecond-granularity Polymarket and Kalshi history - full orderbook snapshots, fills and metadata via ClickHouse SQL, REST or Parquet export.

Contributing

One way in: the issue form. Paste a link, answer four questions. A bot reads it within minutes, checks the link and the repo against the rules, and either adds the entry, closes it with one reason, or drafts it as a pull request for me. It comments as a bot and every decision is a public workflow log. Whatever lands here also lands on the hosted page, rebuilt daily.

CONTRIBUTING.md spells out exactly what gets an entry, section by section, so you can tell before you submit whether the answer is no. How the bot decides is in SPEC.md.

Licence

Code is MIT. Everything in data/ is CC0, so take it, build on it, sell it, no attribution needed. That covers the data describing these resources, not the resources themselves - each one carries its own terms, and a few carry none, which the entries tell you.

Related

• PM Atlas - hosted dashboard mapping the platform landscape.
• jon-becker/prediction-market-analysis - large public Polymarket + Kalshi trade dataset (also listed under Data sources).
• sindresorhus/awesome - the genre this almanac grew out of.

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Generated 2026-11-10 from data/. Found something dead? The refresh bot probably will too, but open an issue anyway.