vendiste a las 6 y compraste las 9?

can someone explain to me where did the $2.5 disappere .
simply i sell 50 $USUAL on spot at 37.5 and the later again i buy 50 $USUAL at 35 so that i made 2.5 difference which mean its profit when i see my spot there is no 2.5 here is the prove so whats going on