I do not think they are that different but they are not close neither. Penny stocks are literally scams if done right, there has been companies with no offices that started out with the funds coming from their penny stocks sold, they make hundreds of millions of stocks and make their company worth millions without actually starting the business but just a promise. It means ICO's are quite similar in that sense, but crypto trading ? I am not too sure.

If the topic was ICO vs penny stock I might have said yes but trading crypto is more like forex than penny stocks at this point. The upper side is not as big as penny or ICO but the risks are lower compared to both. I would say penny stocks have only one more advantage which is having the SEC and IRS with you and if the company scams you they are always caught by the law, crypto people can run away from law longer if needed.