There is a hypothesis that liquidity needs determines short term price action. When more people need cash than they need more savings, general market prices will decline as sellers outnumber the buyers. When the inverse is true it will rise.
And there is a corollary that when liquidity is high money first flows to the most speculative investments because their values are less knowable, at the same time investors are flush and more willing to gamble. For example most won't overpay for GM because its long record gives good reason to believe it will trade in a relatively tight earnings multiple range. But those people may happily overpay for Tesla because its much shorter track record demonstrates that it can trade at almost any multiple. So crypto is like the ultimate expression of that theory, without any binding valuation metrics to hold it down and a history replete with massive bull runs, its catnip for investors flush with cash looking for outsize returns.
If these hypothesis are true, they also work in reverse. When liquidity tightens, people sell the most speculative positions first, so crypto and tech stocks would trail the market.
Not sure how well the data actually matches these hypothesis, the real world is complex and messy with millions of independent agents making independent decisions and being driven by other factors besides a simplistic liquidity == gamble-gamble mental model. So it would be surprising if the effect was so strong to be irrefutable, but anecdotally there is plenty of evidence that can be cherry picked post hoc to support it FWIW.