As you said there is high risk in making high profits but it does not exist where the factor changes. The factor of unstable prices can be determined by doing market research as we have seen that alteration is a part of coin but later on we get profit as a result of high ups in its value. It happens as a result of holding your coins for a long time; if you are not holding then the profit may be less. Otherwise, holding is a best way to make high profits.
In my experience too, we may day-trade with very little risk but the rewards too will be very little. If you refer the factors which are related to risks and when we focus on them I guess those intraday method of trading slowly changes into holding kind of trading. Yes, only very few factors are deciding which is intraday and which is holding type of trading. Still, I agree we may leave off few things in intraday so that we may achieve high performances in short period of time itself.
I do believe the time factor is the biggest differences between intraday and holding. At the same time when we are good in technical analysis and able to catch the end points then time frame may get shrunk into as little as intraday type of trading.