Guys, i'm reading ch. 4 of Advances in financial machine learning. I'm the topic 4.3 (p. 60), the author introduces a way to count the uniqueness of a label.
"
Two labels yi and yj are concurrent at t when both are a function of at least one common return, rt−1,t = pt
pt−1− 1. The overlap does not need to be perfect, in the sense of both labels spanning the same time interval.
"
What does de prado meant by overlap, can someone please help me?