There are different ways investors/traders get dupped by the market manipulators by artificially influencing (inflating/deflating) the price, spreading rumors, creating artificial demand/supply.
Pump and Dump Scheme in Stock Markets Explained
“Pump and Dump” could be defined as a form of microcap stock fraud that involves inflating the price of an owned stock artificially by means of misleading statements so as to sell the cheaply purchased stock in higher prices.