some are saying that some exchanges might increase the price and decrease as they wish. I really hope this is not happening.
In the end it should be offer and demand
Exchanges do play a vital role in up and down of the prices. And like you have said the fee factor matter a lot while deciding the coming price of a coin. On this basis, people are taking the thing and going off of it. Like if bitcoins are high in fees and people can’t afford this thing, how they can continue. Rather they left them. Hence the ultimate results are effected, prices get down immediately.
The reason for the price of Bitcoin is rate of demand and availability, and same things can also be the reasons for fluctuations. The news and social medias can also play a part in fluctuations depending on what they say, though it’s not really good to depend on what they are saying some of the times, cause some are bad news to kick against Bitcoin. Well, those bad news can favor people with patience. Just like what happened in 2017, lots of medias were carrying bad news about Bitcoin and it made lots of people to withdraw, creating a chance for others to invest at cheaper rate.