I do not fully agree but I believe that the investment in your hand should be 70 percent bitcoin as 30 percent altcoin. If you make your whole investment as altcoin or bitcoin, you will miss many opportunities.
Definitely agreed to this quotation that Bitcoin has an ability to raise your investments due to the value of Bitcoin. In some cases Alt coins are already listed in the market and the advantage to it but I much prefer Bitcoin to invest my holdings.