As far as I know the effect of bitcoin price when it goes down is the worry of the majority the word panic. This is the clear effect because profit will decrease also more than half. When it goes up then almost altcoins will become green color. That is how I notice bitcoin price effect.
Factors which affect the price of Bitcoin are changing with the passage of time and in different time intervals depending on the demand of people. Of people demand for the Bitcoin or any other crypto coin or currency then the value of these coins will increase and this increase trend will encourage people to buy and invest in market like this. On the other hand buying Bitcoin or other coins are risky in high market so avoid buying in high market.