SPCX 15 Inclusion Question

Hi I have a question about the 15 day Space X inclusion period where it officially gets added to multiple indexes. I want to focus on the Nasdaq 100. My question is about index funds front running this inclusion. On July 6th the rebalancing is officially completed for the Nasdaq 100 to include spacex. So my question is when do these index funds actually start purchasing? From what I understand these index funds are not allowed to purchase until after 15 days from the IPO so that would land on Ju