Eva - your guess is as good as anyone's as to who/what/where/why that large block was made. When you watch tomorrow your eyes will see that either 1) that big purchase was made to push it up at the open or 2) that big purchase was made to help push it down at the open. Regardless, you won't know what really caused it to happen.
That big purchase could simply have been the stock buyback as you indicated which might have little to no effect. Or, it could have a big effect.
