are the price movements related to those speeches of the central banks such as the BOE?
Your title is different from your question, please don't post this kind of clickbait in this forum.
First, Bitcoin (in theory) is a decentralized, open, borderless, trustless, and censorship-resistant currency. Banks cannot stop bitcoin.
Where
Second, Bitcoin is like any other commodities, its price also affected by sentiments i.e. government comments/policies.