The market has the perception that the powers that be will not allow the markets to falter ahead of the fall elections.
If that perception fails, look out below.
“Blood and power intoxicate; they help to develop callousness and debauchery. The mind then becomes capable of the most abnormal cruelty, which it regards pleasure; the man and the citizen are swallowed up in the tyrant; and the return to human dignity, repentance, moral resurrection, becomes almost impossible."
Fyodor Dostoevsky, The House of the Dead