Originally Posted by thepiper

Those are block trades going through the middle markets dept of a broker dealer. They are (typically) an institution exiting a position where there is no volume. The the middle markets will find a buyer (typically another existing holder by phone) for the whole block at a discount. After the trade is done they have to report it which is why you see it.

In other words, if you put up a bid nobody would ever hit it unless you were to make some relationships in the name that would call you when a block comes up. Also the idea is to cross the block at a discount to someone who won't immediately sell it to maintain price stability. If you got known for flipping, you would stop getting phone calls for block trades.