BTC has already shown its potential this year, but if you compare the raise of BTC with other major altcoins, they are still very silent. I have not mentioned any great price increase, so I hope it will happen in the nearest future.
We see that many altcoins are depreciating against the bitcoin right now. So I think that it's not a good time to sell all your altcoins for bitcoin. It's better to hold and wait for an altseason that will come after bitcoin bull run.