The value on the tape may be the average prive over a few large blocks. If an institution puts in a block order for 500,000 shares the block desk may wind up distributing that to more than one counterparty at slightly different prices.
Mero, doubtful, generally when larger block trades occur (especially on low-liquidity stocks such as SUPG), the blocks are negotiated outside of the market and then put on the tape... those blocks had to have been traded outside the market, I can pretty much guarantee that, otherwise SUPG would have whipsawed pretty hard when they went through (trading what is the ADV at one time generally has that effect:)).
That there were 2 larger blocks traded on the same day after little activity for 2 months is a bit odd, I agree. And we traded 15k at the open... if memory serves correct, we haven't traded 15k in the first hour in quite awhile.