To know of an ICO is a scam look at their roadmap it should be realistic it is impossible to a token to be a skyrocket in a month. The roadmap of the ICO should be on the same pace. Bounty it must not be unreasonably high. If an ICO promises gain on your investment 30–50% higher than market average, it is suspicious. Pre-ICO A project must have a platform that is functioning at least in a test mode. If such a platform exists, this is not a scam. You check it carefully so you will not be scamed