This, of course, depends on your comfort level in the crypto world. Many time, when I've invested in an ICO, it is more for the initial quick flip. There have been a few that I've decided to hold long term, including Seele and DAOStack. And, there have been a few that really burned me. When going into an ICO, do small volumes that you are comfortable with, in case you lose. If you cannot take a lose, just don't do it. Wait for it to hit an exchange, and gauge if it's going up from hype, or a true winner. If hyped, wait for it to fall well below ICO price.