Definitely not safe if you are considering putting huge sums of money into ICO's. What you got to do is research about the team and the project that they are building. The kind of contacts the team has got and the community around it. Most imp is the hardcap. But still after all this you may burn your money.
In terms of security, it's safe, there is no doubts for this. But in terms of other concerns about returns and profits, it's in the gray zone. Sometimes they stay in low prices and get dumped by the participants. That's a huge problem.