Please clarify if this is from high to low or from open to close or some other measure

@Cactus the best method weve found is to only compare the final market close prices. So in this case it would be the close price of the day before the q started to the close price on the last day of the quarter.

So: prior year Dec31-Mar31

Mar31-June30

June30-Sep30

Sep30-Dec31

That way we have exact coverage, and mathematically we can combine intervals. q4(q3(q2(q1))) == y1

This is necessary because often one days close price isn't the same as the next days open price.

@Ernie Thanks

Is this measured from high to low?