Under App Store review

Learn to trade. No real money. No noise.

Finio is a stock market education app with a Python signal processing backend, a real-time demo portfolio, and AI-generated analyst verdicts — built solo, spec to submission.

Try demo account See how it works

Under the hood

Signal pipeline

The verdict on screen is the output of a Python signal processing backend — the same architecture as an embedded sensor pipeline, just with price data instead of sensor readings.

Raw input

OHLCV bars from Polygon.io + live quotes from Finnhub. Redundant sources with local cache fallback on rate-limit — no silent failures.

Polygon.io · Finnhub

Filter

Rolling averages, rate-of-change over 20 bars, z-score normalization against a 60-bar window. Noise removed, signal preserved.

NumPy

Feature extraction

Four channels computed in parallel: momentum, volume pressure, trend (EMA crossover), and volatility (rolling σ).

4 channels

Verdict

Signals scored, weighted, and resolved into an analyst verdict with tagged signal contributors shown in the UI.

Buy · Hold · Sell

# momentum signal — rate of change over 20 bars
roc = (close - close.shift(20)) / close.shift(20)

# z-score normalization against 60-bar rolling window
z = (roc - roc.rolling(60).mean()) / roc.rolling(60).std()

The product

Five screens, one coherent system

From auth to analyst verdict to demo portfolio — every screen is connected to the same live data pipeline. Dark, fast, opinionated.

Stack

⚡ Expo React Native · iOS

🔥 Firebase Auth + Firestore

🐍 Python NumPy signal backend

📈 Polygon.io + Finnhub APIs

🤖 AI-generated analyst verdicts

Home feed

Analyst verdict

Demo portfolio

Profile

Architecture

State machine at the core

The trading session logic is a deterministic finite state machine. Every transition is explicit, triggered by a specific event, and logged — the system always knows exactly what state it's in.

Session states

IDLE

MARKET_OPEN on_open()

POSITION_ACTIVE buy_confirmed()

ORDER_PENDING sell_request()

SETTLED settled()

No implicit state, no silent failures. Every transition is logged and recoverable — the system always knows exactly where it is. That's the design constraint.

Data sources

Polygon.io

OHLCV history · primary source

Finnhub

Live quotes · secondary source

Local cache

Rate-limit fallback · stale-data flagged to user

Real-time layer

Firestore listeners

Event-driven sync across trading rooms — fires on change, not polling

Firebase Auth

Apple Sign-In · email · session management

Try it now

Demo account

Currently under App Store review. Use the demo account for the full experience — live data, analyst verdicts, $10k simulated portfolio.

demo@finio.app

Password

Demo1234!

App Store review in progress