Yes, you are right, but before the ICO there is an increase in demand for Ethereum so the price goes up. For example I bought Ethereum when it was at around 0.09 BTC and then it went up about 50% to 1.14 levels in a few days. I think it was mainley because of the Bancor ICO that happened at that time which raised $150M in an hour in Ether.. then I sold it and it started going down for thw reasons you gave.