Sorry.. I was actually saying that the portfolio should be at least 80% made up of Bitcoin and by mistake I typed altcoin. Many thanks for pointing that out. This is the strategy that I normally follow with any investment asset. I would normally leave 80% to 85% of the portfolio for assets with a lesser amount of risk and the remaining 15% to 20% for high volatile assets. The same strategy was used for cryptocurrency investments as well. Bitcoin is not as volatile as the other cryptos, so I normally have 80% to 90% of my portfolio comprised of BTC and the rest by alts.