A polymarket trading bot that detects temporary pricing inefficiencies across connected Polymarket sports markets.
Who-am-i on Polymarket -> sold-my-car-to-bet
🎥 Watch the trading bot execute live
live.mp4
Have an idea for prediction markets or AI trading? Feel free to reach out.
While building this project I also created:
STAKE-MATH
A Node.js library implementing Kelly-based stake sizing and probability mathematics.
Trading is not gambling.
Trading is probability management.
Without mathematics, risk management becomes guessing.
Many of the position sizing models used here are based on the Kelly Criterion, fractional Kelly, expected value, and bankroll optimization.
Those mathematical foundations have been responsible for far more of my long-term success than any individual trading strategy.
If you decide to experiment with this project:
- start with simulation mode
- understand every trade the bot makes
- test your own ideas
- use small position sizes
- never risk money you cannot afford to lose
Happy Trading ❤️
- ⚡ Real-time Polymarket CLOB streaming
- 🧠 Cross-line arbitrage detection
- 📈 Kelly Criterion stake sizing
- 💰 Paper trading & Live trading
- 🛡 Risk management engine
- 📊 Beautiful terminal dashboard
- 🧩 Modular architecture
- 📝 Structured logging
- 🚀 Production-oriented TypeScript codebase
Sports markets inside a single event should satisfy several no-arbitrage relationships.
Whenever one market reprices faster than another after new information arrives, temporary inefficiencies can appear.
The bot continuously:
Gamma API
│
▼
Discover connected markets
│
▼
Stream live CLOB orderbooks
│
▼
Detect pricing violations
│
▼
Risk evaluation
│
▼
Kelly stake sizing
│
▼
Submit limit orders
│
▼
Track positions & PnL
Current arbitrage checks include:
- Complementary YES/NO pairs
- Totals ladder relationships
- Spread ladder relationships
- Moneyline vs Spread
- Three-way market sums
- BTTS relationships
git clone https://github.com/Poly-Sports/polymarket-sports-arbitrage-bot.git
cd polymarket-sports-arbitrage-bot
cp .env.example .env
npm install
npm run start:simnpm start -- --mode simnpm start -- --mode live --confirm-livenpm start -- --event nba-lal-bos-2026-01-15npm start -- --tag 100381| Flag | Description |
|---|---|
--mode sim |
Simulation mode |
--mode live |
Live trading |
--event |
Watch specific event |
--tag |
Filter Gamma tags |
--confirm-live |
Required safety confirmation |
┌───────────────────────────────────────────────────────────────┐
│ Header │
│ Mode • WS Status • Balance • PnL • Uptime │
├───────────────────────────────────────────────────────────────┤
│ Tracked Markets │ Opportunities │
├────────────────────────────┴──────────────────────────────────┤
│ PnL Chart Exposure │
├───────────────────────────────────────────────────────────────┤
│ Orders / Fills │ Alerts │
└───────────────────────────────────────────────────────────────┘
[p] Pause
[f] Flatten
[q] Quit
Logs are written separately using Pino so they never corrupt the dashboard.
See .env.example.
Important variables:
| Variable | Default | Description |
|---|---|---|
| MODE | sim | sim or live |
| MIN_NET_EDGE_BPS | 50 | Minimum edge |
| MAX_POSITION_USD | 500 | Max Kelly stake |
| KELLY_FRACTION | 0.5 | Half Kelly |
| MIN_STAKE_USD | 5 | Minimum trade |
| MAX_EVENT_EXPOSURE_USD | 200 | Event exposure cap |
| DAILY_LOSS_LIMIT_USD | 100 | Kill switch |
| SIM_INITIAL_BALANCE | 10000 | Paper balance |
Gamma REST
│
▼
Event Graph
│
▼
Market Classifier
│
▼
CLOB REST / WebSocket
│
▼
OrderBook Store
│
▼
Arbitrage Detector
│
▼
Risk Management
│
┌────────────┴────────────┐
▼ ▼
Sim Executor Live Executor
│ │
└────────────┬────────────┘
▼
Portfolio + Dashboard
Live mode requires:
PRIVATE_KEY
CLOB_API_KEY
CLOB_API_SECRET
CLOB_API_PASSPHRASE
and either
--confirm-live
or
CONFIRM_LIVE=true
Execution uses
@polymarket/clob-client-v2
against production endpoints.
src/
├── arb/
│ └── Arbitrage detection
├── config/
│ └── Zod configuration
├── core/
│ └── Engine
├── data/
│ ├── Gamma
│ ├── CLOB REST
│ └── WebSocket
├── exec/
│ ├── Simulation
│ ├── Live
│ └── Order Manager
├── model/
│ ├── Event Graph
│ └── Classifier
├── portfolio/
│ └── PnL
├── risk/
│ └── Exposure controls
├── ui/
│ └── blessed-contrib dashboard
└── util/
├── Logging
├── Math
└── Rate limiting
Contributions are welcome.
Whether you're interested in:
- quantitative trading
- prediction markets
- TypeScript
- market microstructure
- performance optimization
feel free to open an Issue or Pull Request.
If this repository helped you learn something new, consider giving it a ⭐.