They are not 1 - to - 1 correlated.

Nobody really pays attention when the dollar goes down during inflation, because everything is denominated in dollars. Therefore, when you see BTC price go up, that can mean either two things - the market demand of Bitcoin is increasing, or the US dollar is losing value because of inflation while Bitcoin stays at the same demand.

Same is true in reverse - when BTC value goes down, it doesn't necessarily mean that dollar is also going up, perhaps the dollar is remaining at the same value while BTC's own demand diminishes.