Fix YFRateLimitError: Too Many Requests Rate Limiting Issue

[MaxSchoon]

Issue Description

The application is encountering a YFRateLimitError('Too Many Requests. Rate limited. Try after a while.') error when fetching data from Yahoo Finance.

Current Problem

• Data fetching is failing due to rate limiting
• Users cannot retrieve market data
• The error message suggests waiting, but this doesn't provide a good user experience

Expected Behavior

• Implement proper rate limiting handling
• Add retry mechanisms with exponential backoff
• Provide user-friendly error messages
• Consider implementing data caching to reduce API calls

Technical Details

• Error occurs in data fetching operations
• Need to implement proper error handling and recovery
• May need to add delays between requests or implement request queuing

Priority

High - This affects core functionality of the backtesting application

Labels

• bug
• help wanted