This is a thousand times ask in the thread but for the new one's, the value of bitcoins relies on the supply and demand, Since bitcoins has a limited supply in nature, The value tends to pumps up because of it is precious like jewel.
It is normal in business that popularity and demand will matter most like bitcoin popularity gets inreasing in demand nowadays that makes sense precious and valuable on it. And with the big whales strategy in crypto industry they also play a great role of price increase and or decrease but it depends what they want to make them earn more profit.