Option premiums are not that simple to model it has varied factors like IV, VIX, number of buyers and sellers etc, if there is no sellers and only buyers of options even though underline moves in your direction premiums moves opposite. I have seen Put rise up even though Index moved up etc or call didn’t move up even though Index shot up. ONLY one thing is certain <ATM (Out of the Money) will expire to 0 at Thursday 3:30 pm