Sure, but assume for the hypothetical that the counter parties were a list of existing "I'll sell this much at this price" orders. I.e. they were existing information that the market already took into account.

Or 1 million people sold $1 worth of Apple. If you want to execute a large trade, you'd probably have to buy from several sellers, and (my limited understanding of the market is that) you'd do so by matching sell orders in ascending order, thus pushing the market value up.