Correlation Coefficient between bitcoin and a bunch of altcoins

Explanation
The numbers in the matrix are correlation coefficients (What's that?). You have to read them in the following way:

The closer to 1, the more correlation (prices behave similar)
The closer to -1, the more inverse is the correlation (prices move in different directions)
Anything close to 0.0 – Either negative nor positive correlation (movements outweigh each other

This could be the start of a crypto index.