This article was originally published in The Option Strategist Newsletter Volume 16, No. 14 on July 27, 2007.
What Is A “90% Day?”
A “90% Day” must satisfy two criteria: 1) either advances or declines comprise more than 90% of all issues that moved that day (unchanged issues don’t count), and 2) either advancing or declining volume was 90% or more of the sum of advancing and declining volume.