please do not disturb- shortsellers at work, page-9

short sellers have a simple method, sell at a short term loss, by doing so you start a panic, then re-buy at their desired price and wait, once they reach a good sound profit they sell-out. This could be done by 1 person or a group.
Ramping is the opposite
keep buying available shares at rock bottom, (by doing so you attract alot of attention) once you reach your sale price, you dump it all at the highest price, that way you would have sold most of your shares at a higher profit, again, this could be done by 1 person or a group.
This is my understanding of manipulating the market.