100% bitcoin, altcoins is very risky, most of them can't increase with bitcoin.
ETH had peak of 0.15 BTC this year, went 0.7BTC and now its 0.2BTC.
Some altcoins increased more than bitcoin, but it is very risk to hold it.
Holding bitcoins is the best choise, i bought 30% in altcoin and regret it.
I hate to amit it but I have come to this conclusion the hard way.