SEC Diff uses Wikipedia's diff engine to render diffs of SEC filings from one period to the next. The tool is useful for uncovering subtle changes in corporate strategy that management may not mention elsewhere. Lean more about Wikipedia's diff algorithm here.
- Download ZIP file from GitHub (see link to the right titled "Download ZIP").
- Unzip into directory
- cd into directory and
npm install
Go to the SEC website and grab the url for a filing from two different time periods. For example, the following two urls link to BazaarVoice's form 10-K filed in 2015 and 2014, respectively:
- https://www.sec.gov/Archives/edgar/data/1330421/000119312515235103/d929871d10k.htm
- https://www.sec.gov/Archives/edgar/data/1330421/000119312514251125/d698757d10k.htm
Navigate into the root directory for your install. The following command will download the filings, convert them into plaintext, and fire up an expressjs instance on your local machine (n stands for new, o stands for old):
node app.js \
-n https://www.sec.gov/Archives/edgar/data/1330421/000119312515235103/d929871d10k.htm \
-o https://www.sec.gov/Archives/edgar/data/1330421/000119312514251125/d698757d10k.htmWhen you see Server is running on port 3000 in your console, open a browser
and navigate over to http://localhost:3000/ to view your diff.
The script takes a few seconds to load, depending on the size of your SEC filings.
Diffing tables may be unecessary because tables generally include data for multiple years. Modifying node-html-to-text to ignore tables is not difficult.
You don't need to parse the filings every time to launch the app. If you've run the above command successfully you may launch the express server directly with:
node app.js -l true