RSquared is the Correlation Coefficient from Linear Regression.
It is used to determine how much of the price action over the
specified period can be explained by the regression line, and how
much should be attributes to random noise. RSquared ranges from
0 to 1.The higher RSquared is to one, the closer prices have fit to
the linear regression line. During strong trends, RSquared will
remain above 0.5 for an extended period of time.