Nothing is safe in a worldwide and decentralized crypto currency market. It would be also new for me that trading is safe, because if you win money with trading, then someone else must lose it. However, if you like long term trading I suggest to do it with new and low priced coins, because they have the option to do the same like bitcoin did. But if the price of a coin is already in the height of $ thousands, it is of course difficult to reach high winning rates.