i am not a day trader , so i dont know much about these terms.,
there was trollbox on polo where people used to say pump and dump specific coins. but trollbox is gone now.,
from basic understanding dump means DROP,
does the PUMP means buy ?
I think a pump typically means that an individual or group is driving the price up by buying a bunch of coins so the price is artificially inflated. This could make others jump in to buy at these high price as well.
Then after other buyers drive the price higher, the individual or group that pumped the price begins to sell at these high prices which is called a dump and then the price drops leaving the other buyers with lower priced coins.