caney, any trade that is over 6 times NMS is delayed 1 hour.
This is to keep an orderly market, so you cannot see large trades at the time they are made. The effect of these delays on a rising price is the "USELESS" computer generated buy/sell as seen above in the post by MG, or as seen on AFN or M am etc.... is they "show" buys as sells on a rising price, and sells as buys on a falling price.
The only way to actually work out whats happening is to look at the actioned time (eg the time of the actual trade and not when it was reported) and then see what the bid and offer were at that time.
A trade over 60 times NMS (I think, might be more) can be delayed reported by up to 5 days.
So trades of up to 5.9 times the NMS must be reported within 3 mintues of happening (still enough time to make the computer software report it wrong on a quick moving price change).
Trades of 6 times NMS or over will be delayed 1 hour.
Trades of 60 ? times NMS or mover can be delayed days before being reported.