I suggest that it is not a good idea to sell all your altcoins that you are holding just because BTC price is raising.  I suppose that you must give altcoins a good chance for their price will go up too, like BTC. However, it still had better divide your investment, maybe you could sell some altcoins to buy some BTC to reduce the huge risk of your loss and gain more if it could. Everything depends on your own choice! Let's do the best!