I am not sure this is a god strategy, I have 5-6 coins, and try not to keep more than that as it becomes impossible to keep following the coin's news.
Is holding up to 5-6 coins only too risky ?
how many do you hold and what is your rationale for that number ?
i think its not too risky to hold 5-6 coins because you can easy to manage the coins itself and you can make decision for selling or just hold for a long term. if you have more budget, then maybe you can use for trading and keep that 5-6 coins for long term and you can use the other coins for daily trading.
I think its depend on how much your budget and how good you handle each coins, if you are newbie in trading, I suggesting to hold until 7 coins but its up to you. if you think you can hold until 10 coins then go a head but if not, I think 5-6 coins is enough for you. its better to hold for a long term as in the end, you can make big profit.