To an extent you are right. but not always. My order for SO4 WAS...

To an extent you are right. but not always. My order for SO4 WAS placed as a limit order at a reasonable price within an anticipated reasonable range and had been in the queue for days.. That one pip one share transaction lowered the price. Without it the price would have been one pip higher. If the buy order had been for more than one share then more of my order would have been filled. Seconds before the end of the auction time it appeared that my order was .5c below the probable outcome and would not be activated.