Indeed investing in an ICO is risky, which is also why it can yield high profits. What you can do to minimise this risk is to do a lot of research into the ICO, the product and its team before deciding to invest in them or not.
Well there probably are more bogus icos than legitimate ones so yeah you have to really put in time and effort ib studying an upcoming coin if you plan to invest on it. Many people probably have gotten wealthy after investing in the right ico but it isn't as simple as is sounds.