Mostly new traders get excited on seeing their invested coin's price going high.Without realizing that it is being pumped and it would be soon dumped,they just follow its price without finishing the trade.
Suddenly when the pumped coin reaches its high limit and gets dumped by the group which pumped it,the price just starts to fall rapidly.These new traders would immediately place sell orders but of no use as the price would fall much faster than the sell order price.At last,they would sell their coins at a much lower rate than which they bought.
In order to avoid this,they should set a profit limit of 5% or 10% and as soon as they reach that limit,they have to just finish the trade.By this way,they could avoid greediness and losses.