I never want to invest on any of altcoins by selling my bitcoins because I knows that bitcoin has more potential than any other coins so it will give more benefits in future if we hold until,if you invest on altcoins you can invest the amount from profits of your bitcoin.
Bitcoin has always had potentials and always will. I cannot say that one should sell all altcoins anyway, but at the same time, it is necessary to always stay careful as much as possible, knowing that even if you are investing in any altcoin, you really want to be investing in an altcoin that you are sure do have huge support and looking at some of the things that happened last year with most of the altcoins hitting bottom low when bitcoin started a bull rally, it is not a guarantee that something like that will not happen again.