How we built Israel's most-downloaded stock trading app
IBI Investment House came to us with a problem: Israeli retail investors had no good way to trade US stocks from their phones. The existing platforms were clunky, slow, and designed for desktop. IBI wanted something that worked for both first-time investors and experienced traders.
We built IBI Smart from initial specification to App Store launch. The result: 500,000+ downloads, a 4.9-star rating on Google Play, and the highest user retention rate of any trading app in Israel.
The technical challenge
Building a stock trading app is not like building a typical consumer app. Every feature touches real money and is subject to financial regulation.
Real-time market data. Stock prices move every millisecond during trading hours. The app needs to display live prices for thousands of US-listed securities with sub-second latency. We built a WebSocket-based data pipeline that handles 50,000+ price updates per second during peak market hours.
Regulatory compliance. Israeli financial regulations (ISA) and US market regulations (SEC/FINRA) both apply. Every transaction, every screen, every notification has to be compliant. We worked with IBI's compliance team throughout development, not just at the end.
Security architecture. Users link real brokerage accounts. The app handles PII, financial data, and authentication tokens. We implemented certificate pinning, biometric authentication, encrypted local storage, and real-time fraud detection.
What the app delivers
Instant account opening. Users complete digital onboarding in under 5 minutes, including identity verification and regulatory disclosure acceptance. No branch visit required.
AI-powered analysis. Integration with TipRanks gives users access to analyst consensus ratings, price targets, and financial report analysis. Users see not just prices but context about what's driving them.
Real-time trading. Buy and sell US stocks and ETFs during market hours with real-time order execution. Limit orders, market orders, and stop-loss orders all supported.
Portfolio analytics. Performance tracking, dividend history, asset allocation breakdown, and tax-relevant reporting — all calculated in real time.
What made the partnership work
Two things differentiated this project from a typical client engagement:
Embedded teams. Our developers worked alongside IBI's internal team from day one. Joint standups, shared Jira boards, unified code reviews. The external team wasn't "external" — it was part of the product org.
Domain investment. Before writing a single line of code, our team spent three weeks learning Israeli securities regulation, brokerage operations, and market microstructure. You can't build a trading app without understanding how trades actually settle.
The numbers
- 500,000+ downloads across iOS and Android
- 4.9-star rating on Google Play (4.8 on App Store)
- 85% 30-day retention rate (industry average for fintech: ~25%)
- Zero compliance incidents since launch
- Sub-200ms average order execution time
Frequently asked questions
How long did IBI Smart take to build? From initial specification to App Store launch was 8 months. We had a working beta in 5 months.
What tech stack did you use? React Native for the mobile client (shared codebase for iOS and Android), Node.js microservices for the backend, WebSocket for real-time data, and AWS for infrastructure with multi-AZ deployment for high availability.
Can you build similar apps for other financial institutions? Yes. The technical patterns we developed for IBI Smart — real-time data pipelines, regulatory compliance frameworks, and security architecture — are reusable across fintech projects. Let's discuss your project.