Alternative cryptocurrency prices fall when bitcoin begins to rise, this is a long-established trend. A huge number of people at the time of growth are moving from alternative to bitcoin. Typically, alternative cryptocurrency grow when Bitcoin is sideways. So now the future of alternative cryptocurrencies is blurry and not clear, now there is a panic that there will be no rise in prices for alternative currencies.
The panic happens when the market started the correction, I believe it started in the 2nd half of 2018 because I observed my portfolio is also going down.
I am still hesitant in selling my holding despite seeing the price dump because the history is good for the whole market, but that FOMO that cause a new ATH for BTC and most altcoins resulted to a disaster after the correction.
However, it's not correct to panic and dump your altcoins especially if you still believe that the team is still actively developing it, maybe the time has not come yet for altcoins to move its usual positive movement, but eventually it will arrive, so it's future is not blurry.