Many people say that the prices of the alternate cryptocurrencies are reducing because of the reduction of BTC prices. Bitcoin is know as the first crypto currency but other alternative currencies such as Eth, Ripple, Lite works as individual platforms. Therefore how the other crypto currencies depend on BTCs?
I think the problem is that for the time being we still don't have a single coin that has it's priced entirely based on their use case. So basically, prices as based on what people expect them to do in the future, so the majority is still speculation. Since speculation is all that they have in common, it means that whatever bitcoin does, the others will do as well, so that everything remains proportional.
In the future, when these coins are up and running, and being valued almost solely on their use case, this correlation will probably end, because as long as they keep doing what they promise they will remain their value.