Personal Market Monitoring Terminal

The problem

Following ETF holdings changes, volatility, yields and sentiment in one place, with history kept and every number explained in plain English.

What I built

Sole designer and builder.

Features

• ETF holdings monitor with diffing, immutable reference entry prices and lifecycle history
• Composite market sentiment score (0-100) with component breakdown
• VIX term structure and regimes, yield curve inversion/steepening detection
• Paper-trading strategy leaderboard on genuine holdings additions
• Two-stage DCF calculator and fixed-fractional position-sizing calculator
• Data Health page fed by an ingestion run log

Integrations

• Free public data providers behind swappable interfaces (iShares, FRED, CBOE, Yahoo, Stooq)
• GitHub Actions cron ingestion
• Telegram Bot API (alerts planned, not live)

Decisions I made

• Never show fake data: unavailable metrics display an explicit reason
• Append-only snapshots enforced with database triggers
• Every data provider sits behind an interface so free sources can be swapped for paid ones
• All financial math in pure, unit-tested functions

Outcome

A single-user 'Bloomberg Terminal Lite' that ingests free data every 3 hours, keeps an append-only history and explains every metric in plain English.

Stack

Next.js · TypeScript · Tailwind CSS · Prisma · Supabase Postgres · Vercel · GitHub Actions · Vitest