For me IEO are way more safe rather than ICO, but i mean only IEO on top exchange. Like Binance Launchpad IEO, Binance are major exchange and i mostly put my assets in that exchange, atleast 40% of my total assets. I almost participating on all event on Binance launchpad, but it's not that easy to win the Lottery.
If you don't have plans to trade daily, you should not store your money on exchanges. Because we all don't know what will happen, right? Binance is a reliable exchange, that compensate for users when the exchange or user account got hacked; but we should not expect such things all the time.