if it opened higher, then it drop more. which means WS is still not happy with the drop of the rating.
If it is opened lower, then move high, which means WS is at least happy short term. the opening is more the opposite of what WS think, what matter is in the day, when the big guys is playing, the big guy scare you out at the beginning then accumulate.
The drop of the mortgage is a side confirm.
Of course, this is just an early sigh of bottom, need a confirmation in 3-7 days. that is when more prudent investors jump back in.