you need to read up more

today is rebalancing day last day of Q2 2024 SMCI has left russell index to join S&P500 so all the etfs that had SMCI those etfs would have a lot of SMCI shares because of the explosion in its market cap over the last 1 year so today they have to sell it all and that is a large large volume

I wouldn't worry about it next week it should rally again