diversification will be a good idea with one's investment but it won't be less stressful. This will only be a good idea if you will be having the right choices but if you will just choose coins which are just popular in this market, profit won't be always earned since there is an inconsistency regarding the price movement of cryptos having no correlations at all. Efficiency of this strategy depends on the variation of your investment. But it will be hard to avoid losses in any investment so maybe, it would make it less stressful, somehow, if you will also set a stop loss.