Every action you take in crypto currency trading or investing holds a high risk factor but also can bring in high rewards. I personally do both because once I have purchased a coin or token in an ICO eventually I will trade it for bigger gains, so in the end I do both of these tasks. I also like dividend or revenue generating tokens or coins as well, that grow a passive income also for the longer term, along with actual price appreciation factors.
But ICO investing comes with more riskier than trading altcoins sometimes when the tokens are listed in exchanges the price will be less than the ICO price so we need to pick the right projrcts if we want to make money.And many ICOs are turned to be a scam project once they got their desired value of money so we may lose our investments too.But in altcoin trading we can make less profits than ICOs but we can make if we have the appropriate knowledge.So people who have the knowledge of trading is better to go with altcoin trading than investing on ICO.
ICO is a bit more risky compared with altcoin trading but we can't say altcoin trading is risk free. It's also very risky. Decreasing the risk will be linked to your own decissions here.