Frequently Asked Questions
Common questions about the Chart Pattern Matcher and API usage

How does the pattern matching work?

The system compares chart patterns using Dynamic Time Warping (DTW) algorithm, which measures similarity between normalized price movements. It compares against 2000+ tickers to find the most similar patterns.

What is the offset parameter?

The offset shifts the comparison window in time. For example, with a +30 day offset, the system compares your ticker's pattern from Jan 1-31 with other tickers' patterns from Jan 31-Mar 2.

Is there a rate limit?

The API is completely free to use with no authentication required. However, Yahoo Finance may rate limit requests if too many are made in a short period. The system includes automatic delays to minimize this.

Can I use this for commercial purposes?

Yes, the API is free to use for both personal and commercial purposes. No attribution required, though it's always appreciated.

What data source is used?

Historical price data is fetched from Yahoo Finance's public API. Data is typically delayed by 15-20 minutes for real-time quotes.

How accurate is the pattern matching?

The accuracy depends on the quality of the input pattern and the time period selected. The system uses advanced algorithms to normalize and compare patterns, but results should be used as a starting point for further research, not as definitive trading signals.

Can I compare patterns across different time periods?

Yes! The offset parameter allows you to shift the comparison window forward or backward in time. This is useful for finding patterns that occurred at different times relative to your reference pattern.

What file formats are supported for image uploads?

The system supports common image formats including PNG, JPG, and JPEG. The image processing extracts the pattern from the uploaded chart image and converts it to coordinate data for comparison.

Note: This tool is for informational and educational purposes only. It should not be considered financial advice. Always do your own research before making investment decisions.

Built with v0