DIFF13F

DIFF13F is a minimal Dash app to explore quarterly 13F filings, view top positions, track changes between quarters, and visualize holdings over time.

✨ Features

• 📊 Explore top positions in a single quarter
• 🔍 Spot largest changes between two quarters
• 📈 Track top positions over time with line plots across multiple quarters
• 💻 Minimal web interface powered by Dash

🛠️ Installation

Make sure Python 3.9+ is installed with pip.

Install the diff13f library:

 pip install git+https://github.com/Noe-AC/diff13f.git

This will add the diff13f command to your PATH.

🧩 Requirements

Python libraries (installed automatically via pip):

• dash and dash-bootstrap-components: the interactive web interface.
• plotly: for plots.
• pandas: data loading and manipulation.
• polars: optional high-performance DataFrame library.
• xmltodict: parsing XML-formatted 13F filings.

💡 Usage

1. Launch the app:

    diff13f

2. Import the 13F .txt filings.
3. Explore the data in the app.

📄 Data source

To use the app you need complete submission text file (13F filings .txt files). These files are typically named something like 0001037389-25-000034.txt.

You can find filings by looking up the company on the SEC EDGAR website. For example:

• 0001037389 - Renaissance Technologies
• 0001067983 - Berkshire Hathaway
• 0001350694 - Bridgewater Associates
• 0001423053 - Citadel Advisors
• etc. (just take any of these URL and substitute the CIK).

⚠️ Limitations

Starting from 2013-q2, SEC 13F filings use XML inside the complete submission text file, which DIFF13F parses reliably.

Earlier filings use a fixed-width format (FWF), harder to parse and not fully supported:

• FWF files for Renaissance Technologies and Bridgewater Associates are partially supported.
• FWF files for Berkshire Hathaway fail to parse and are therefore ignored by the app.

📸 Screenshots

⚖️ License

This project is licensed under the MIT License — see the LICENSE file for details.