Stock Management software is an application developed to assist users in effectively managing and recording stock trading transactions.

Built with Kotlin and integrating SQLite database through the DatabaseHelper class, the software provides a user-friendly interface with key features such as adding purchases (AddMuaActivity), sales (AddBanActivity), tracking stock inventory (TonKhoAdapter), and exporting reports as PDF for archiving or sharing.

The application starts with the login screen (LoginActivity), where users enter their password to access, and also supports functions such as changing passwords, backing up/restores data via SAF (Storage Access Framework), and deleting data when needed.

Users can customize transaction fee rates (buying fees, selling fees, taxes) and change the language (Vietnamese, English or Chinese) to suit personal needs.

After logging in, the main screen (MainActivity) uses ViewPager2 and TabLayout to display three tabs:
1. Overview (Summary),
2. Buy Transactions,
3. Sell Transactions.

The Overview tab provides comprehensive information such as total buy and sell value, transaction fees, investment performance, and inventory list with indicators such as remaining quantity, average stock value, and profit/loss ratio.

The transaction tabs display details of each transaction with stock code information, transaction date, quantity, price, amount, and fees.

When adding a purchase, the user enters the stock code (limited to 5 alphanumeric characters), purchase date, quantity, and price; The application automatically calculates the purchase fee based on the set fee rate (default 0.03%) and updates the inventory.

Similarly, the sell transaction allows selecting a stock symbol from the inventory list (via Spinner), checking the remaining quantity to avoid overselling, and calculating the selling fee (including 0.03% transaction fee and 0.1% tax).

The average remaining stock value is automatically calculated by the software based on total value and quantity, helping investors make accurate decisions.

The PDF export feature (MainActivity) allows creating detailed reports from the currently selected tab, using the iTextPDF library with Roboto font supporting Vietnamese. The report includes a title, date of issue, and data table (e.g. overview with profit/loss ratio, list of buy/sell transactions), with page numbers in the right corner. PDF files are named by language and time (e.g. "TongQuan_2603.pdf" or "Summary_2603.pdf") and saved via SAF, ensuring flexibility when sharing or archiving.

The software does not collect any transaction information from users, ensuring privacy.

Data is saved locally on the device, with a manual backup option to prevent loss. Friendly interface with Vietnamese standard number formats (thousands separator with dots, decimals with commas), and intuitive colors to distinguish lines and financial status (profit/loss).

This is the ideal tool for individual investors who want to manage their stock portfolio scientifically, transparently, and not rely on online services.