It is true that bitcoin  influences the full crypto market. I think it is because  all altcoins price are calculated  in terms of BTC. Which make the price depend on Bitcoin. 

I am not buying right now as i is very risky. I know BTC can go even further to 40k or 50k. But i cannot  buy right now. But in long term perspective  BTC price will go up and up. For long term one can buy BTC any time at any position because  its demand is increasing  day by day.