My classmates asked that question and the professor kept on talking about the probability of getting scammed but he's really against the whole crypto-currency movement so his opinion is biased.
So...here I am, asking for guidance...
As know and i am also a trader in my experience there nothing scamm in trading i am not sure if they have scammers in trading because trading is buy and sell altcoins.
To avoid this scenario do not use unreputable exchange, there so many trusted exchange have an give high security to the users investment.