ORM: Usage of ORMs, such as JPA, is strongly discouraged. Please use SQL queries and include the DDL scripts as well.

Security: Since this is a simulated application, security is not a concern.

Example GitHub Repository:

crypto-trading-sim/
├── README.md (Instructions on how to run the application)
├── requirements.txt (Dependencies for the project)
├── frontend/
│ ├── index.html
│ ├── app.js (Frontend JavaScript code)
│ └── styles.css
└── backend/
   └── Java Spring project

Screenshots:
A screenshot of the initial application screen displaying the top 20 cryptocurrency prices.
A screenshot of the user interface for buying and selling cryptocurrencies.
A screenshot showing the updated account balance after a transaction.
A screen recording demonstrating a user journey through the main functionalities of the platform.