Bitcoin Portfolio Tracker

A sleek, minimal single-page application that visualizes your Bitcoin portfolio performance over time. Track your BTC holdings with real-time pricing and historical data analysis.

Features

• 📊 Real-time Bitcoin pricing with smart caching
• 📈 Historical portfolio tracking with 10+ years of price data
• ⚡ Fast loading with optimized data storage
• 🌙 Dark theme with Bitcoin orange accents
• 📱 Responsive design for all devices
• 🔧 Configurable portfolio size via URL parameters

Coming Soon

• 📊 Interactive charts and visualizations
• 📅 Multiple time windows (1d, 7d, 30d, 3mo, 6mo, 1y, 5y, all)
• 💰 Advanced metrics (Total % gained, Total USD gained, CAGR)
• 🔄 Trade tracking with buy/sell dates

Quick Start

Option 1: Development Server (Recommended)

# Clone or download the project
git clone [repository-url]
cd gainz

# Start development server
make dev

This will install dependencies and open the app at http://localhost:8080

Option 2: Direct File Access

Simply open index.html in your web browser. Note: Some features may not work due to CORS restrictions.

Usage

Basic Usage

Open the app to see your 1 BTC portfolio value with current Bitcoin pricing.

Custom Portfolio Size

Add a btc parameter to the URL to specify your portfolio size:

• ?btc=2.5 - Track 2.5 BTC
• ?btc=0.1 - Track 0.1 BTC (100,000 sats)

Examples:

• http://localhost:8080?btc=2.5
• http://localhost:8080?btc=0.05

Development

Available Commands

make dev           # Start development server
make test          # Run unit tests
make test-watch    # Run tests in watch mode
make test-coverage # Generate test coverage report
make clean         # Clean dependencies
make help          # Show all commands

Project Structure

gainz/
├── index.html              # Main application
├── btc-prices.json         # Historical price data
├── js/
│   ├── data/               # Data services
│   ├── business/           # Business logic (coming soon)
│   ├── ui/                 # UI components (coming soon)
│   └── app.js             # Main coordinator
├── css/
│   └── style.css          # Styling
└── tests/                 # Unit tests

Technical Details

• Pure JavaScript with ES6 modules
• No build step required for production
• CoinGecko API for real-time and historical Bitcoin prices
• Smart caching (1-minute cache for current prices)
• Optimized data format (75% smaller than standard JSON)
• Comprehensive test coverage with Jest

Data Sources

• Current prices: CoinGecko API (free tier, no authentication required)
• Historical data: Pre-loaded JSON file updated daily via GitHub Actions
• Price history: Daily closing prices from 2014 to present

Browser Support

Modern browsers with ES6 module support:

• Chrome 61+
• Firefox 60+
• Safari 10.1+
• Edge 16+

Contributing

For development details and technical documentation, see CLAUDE.md.

License

MIT License - see project files for details.