Pennywise

Investment Portfolio Recommendation Web Application.

Features

• Provide investment portfolio recommendations based on Yahoo Finance data.
• Portfolio comprised of ETFs, shares, and bonds.
• Friendly UX/UI with risk and horizon sliders.
• Historic portfolio performance graph (1, 3, and 5 years) with gain/loss indicators.
• Persist custom portfolio analyses in MongoDB for logged-in users.

Tech Stack

• Next.js with TypeScript for frontend and backend (API routes).
• Yahoo Finance integration via yahoo-finance2.
• Recharts for data visualization.
• date-fns for date handling.
• Clerk for authentication and user management.
• Vercel Analytics for real-time traffic insights.
• MongoDB (via Vercel integration) for persisting custom portfolio data.

Setup & Installation

npm install

Node version

Pennywise requires Node.js v18.14.0, v20.x, v22.x, or v24.x and above. Node.js v23.x is currently not supported by our test tooling.

You can automatically switch to the LTS version (v22.x) with nvm:

nvm use

Development

npm run dev

Open http://localhost:3000 in your browser.

Build

npm run build

Run

npm start

Scripts

• npm run instructions: Display usage instructions.
• npm run dev: Run in development mode.
• npm run build: Build for production.
• npm start: Start production server.
• npm test: Run unit and integration tests.

Testing

Run unit and integration tests via Vitest:

npm test

Environment Variables

The app uses the following environment variables (create a .env.local file):

# Google Analytics (gtag.js)
NEXT_PUBLIC_GTAG_ID=AW-17250895076

# MongoDB connection string
MONGODB_URI=<your_mongodb_uri>

API

GET /api/portfolio

• Query: tickers (comma-separated symbols, default BND,VOO,AAPL), years (e.g., 1, 3, 5; default 5).
• Response: time-series per symbol using Yahoo Finance chart.

Example:

{
  "series": [
    {
      "symbol": "VOO",
      "points": [
        { "date": "2023-01-01T00:00:00.000Z", "close": 377.45 },
        { "date": "2023-01-08T00:00:00.000Z", "close": 381.12 }
      ]
    }
  ]
}

Notes:

• Uses chart(range, interval) with range = <years>y; interval is 1wk for years >= 5, otherwise 1d.
• The app computes aggregate performance client-side using the selected tickers and current risk/horizon.