I think to have a bull market up-coming is the best way to move all the money that you have in altcoins to bitcoin, because with market dominance of Bitcoin the market will go green, and the bull run with start, as far as I am concerned from the previous experience of the bull run more than 55% bitcoin was dominant in the market.
Suggestions?
That was not the best suggestion, at all, but you know, it was better than keeping holding your altcoins, they are much cheaper now.
Also I think any time to switch to Bitcoin only is the right time. Maybe we should never switched to altcoins or ICOs and Bitcoin may have had healthy rising all the time