I will advice you to sell your altcoins in your bag as soon as you see profit and invest all the money into bitcoin. You can see for yourself how the price of bitcoin is pumping and currently, the price is $93k. This should be a good reason for you not to sell those bitcoin you already have because in future, bitcoin price will go to the moon. Selling and buying back is good, if you are lucky to do it right but I don't like such practice, since it makes you have the mindset of a trader. Instead, continue buying more bitcoin to the ones you already have for the increment of your portfolio. The future of bitcoin is very bright.