In my opinion, it is better not to liquidate your bitcoins. If you want to invest in altcoins you better use a small number of your bitcoins to buy some altcoins which have strong fundamentals. No one knows for sure if bitcoin has reached its peak, it could be that in the future the price of bitcoin will continue to increase. therefore it is better for you to save bitcoin
The high valuations of various altcoins are not justified by their userbase, volumes or acceptability. Bitcoin remains as the no.1 cryptocurrency in terms of these parameters, and the gap between Bitcoin and the other alts is just too huge. That means that the current valuation of various alts are inflated.