The lack of imagination is surprising here sometimes.  Poster morningstar gave a detailed explanation of the effect a large buyer's share quantity would have on observing eyes watching a level2 display, yet people still don't know how prices could be manipulated up?  If big shares show on the offer it can put downward pressure on a stock out of fear.  If big shares show on the bid side it can put upward pressure on a stock out of anticipation.  Real orders or not HOGAN, people look at this all day long, and markets can & do get manipulated with SIZE as just a single example.  Not hard to do.

(From your post)

I don't quite understand how traders can manipulate a SP upwards (if they even can)