A fully console-based stock market simulator written in Java. It uses design principles like MVC and Observer Pattern and is designed to simulate buying/selling stocks, updating stock prices, and tracking gainers/losers. 🚀 Features
👤 Single user portfolio management
📦 Buy and sell stocks
💹 Real-time stock price updates with change tracking
🔔 Observer pattern to notify users of price changes
📊 Displays top gainers and losers based on price change
🛠 Tech Stack
Java 17+
Object-Oriented Programming (OOP)
Design Patterns: MVC, Observer
📁 Project Structure
StockMarketSimulator/ ├── Main.java # Application entry point ├── StockMarket.java # Subject + Market logic ├── Stock.java # Stock entity with price tracking ├── User.java # Observer + portfolio logic ├── Observer.java # Observer interface └── Subject.java # Subject interface
✅ How to Run
Clone or Download the project
Open in any Java IDE or use terminal
Compile all files: javac *.java java Main 🧪 Sample Flow
===== Stock Market Simulator =====
- Buy Stock
- Sell Stock
- View Portfolio
- Update Stock Price
- Exit
Example: Buy AAPL, update its price, and see it appear as a top gainer.
📦 Design Patterns Used
Observer Pattern: User observes StockMarket and gets notified when prices change
MVC:
Model: Stock, User
View: Console output
Controller: Main.java handles flow
🧠 Possible Enhancements
Add multiple users
Export portfolio to CSV
Add persistence (save/load portfolio)
Build GUI (JavaFX / React + Spring Boot)