What is this?

myIndex was born out of idle curiosity and a love for graphs.

The idle curiosity was how groups of companies have performed over time. These companies might be grouped by region, indsutry, leadership, name, or any of a hundred other factors - I just wanted to know what the data looked like - thus the graphs.

How Does it Work?

It's pretty simple. myIndex uses a market-capitalization weighting system to calculate a stock index based on given stock symbols. The greater a company's market capitalization, the heavier it weighs on the index. There are at least two other ways to caculate a stock index, but the market-capitalization method is the most widely used and best represents the health and performance of a group of stocks as a whole.

Disclaimer

This tool is for entertainment purposes only. Don't even think about making any financial decisions based on this data. It is 100% guaranteed to be inaccurate.

For one, the calculation of a stock index depends on the number of shares outstanding. There is almost no accurate historical data in machine-readable format for a company's historical outstanding share figures. I've used the best data I can, but I'm certain that most of it is slightly off, and much of it might be totally wrong.

No peer review process has gone into this system. Few security measures have been implemented against the data being tampered with. No verification has been done that the historical data used is, in fact, accurate.