These were the 3 changes that I was aware of earlier in the week that would be changing in the SPX. The 3 adds had like 30x or more increase in volume on Friday and were all down somewhat hard. Similar to deletes. There may have been other factors involved for all 505 issues since a rebalance also means they change the contribution weighting for each issue included. For example, if Apple is high it may drop some and a lower tier component may rise, but I am not familiar with the exact process. I was just pointing out that the Quad Witch and a delayed rebalance from 1st Qtr added to total volume traded. I would guess if we looked at all the SPX components on Friday, the final 1 minute bars would show big spikes. TYL one of the adds shows this with more than half the days trading volume in the last minute.