Bitcoin's price can easily be manipulated by whales, I would believe so. Because they can easily pump in cash to amp the price, or withdraw some of their bitcoins to dump bitcoin's value. Bitcoin is indeed decentralized but personalities, shadow figures, and these whales are the newest form of institutions that can artificially lower its price. Good thing about this though is the fact that bitcoin is a for-everyone currency, so it thrives in the amount of supporters and holders it gets. This means that we can counterbalance the power bag holders have over bitcoin with numbers advantage.
No but there are far better avenues to manipulate the prices.
FUD being the most obvious, lack of research by the average investors puts them vulnerable to many kinds of FUD and results in them panic selling.
There has been evidence that Mt Gox operated bots to artificially game the price before their collapse. I wouldn't rule out exchanges to not be having a hand at any potential market manipulation.
Can't emphasize how big the power of misinformation is over the cryptocurrency industry. One bad story about bitcoin that could reach a huge amount of people could literally shift the market down to a crash. Of course there are other factors like pandemics just as what happened last year. But nothing beats FUD.
