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for me it is 5-10% but I'm planning to push it up to 20%. More I wouldn't recommend since the alt-potential is so huge and diversification is very important (not only for the gains but also for to losen this dependency on one single coin that might drive you crazy when you have this price swings)

Ive got bitcoin by cloud mining and some profitable trades so price its not so important I love amount.

well you for sure wont be doing much wrong with holding BTC for this year.

I have been holding only btc as well, unfortunately I got in only in september 2017 and bought until almost 1.15BTC. About a month ago I started to diversify my holdings and now I have a value of 3 BTC without any additional investments, so thats about the amount ;-)

Diversification is really importnat, not only for cryptos but also in general, maybe you want to give it a second thought.

as I said only a part of my portfolio is in BTC I have KCS ETH EDO XEM SGR BTX