Dumping every end of the day?

I see MM do block sale at the end of the day frequently than just every Friday. No confidence in the market to keep it overnight? I also see a block buy at 8:58 before market opens… I thought no settlement is done before 09:00 for DBS today. What’s going on? $OCBC Bank(O39.SG)$ $DBS Group Holdings(D05.SG)$ $UOB(U11.SG)$