The value of any financial asset, like money, is always and everywhere about expectations of the future. All financial assets are just promises, written on bits of paper. They are commitments about the future, and nothing more, and those commitments create expectations, and those expectations are what determine the demand for those financial assets. What happens right “now”, in the “current period” is always irrelevant, except insofar as it affects expectations of the future.
For monetary theorists who write down models, this creates another degree of freedom. You can say that a Fed action/statement of X will have an effect on expectations of Y, and this will have consequence Z for the economy. You can get just about any sort of result that way, and if you review the literature you will see that theorists have, indeed, gotten all sorts of results–one theorist can say that policy X will raise prices, and another theorist can say that policy X will lower prices.
Personally, I would use that degree of freedom to say that, to a first approximation, any Fed action/statement has zero effect on expectations. My view appears to be clearly false, in that investors hang on every word of the Fed, and Fed announcements often move markets–for a day or so. Then they go back to looking at other news. Whether there is any durable effect on markets is something you can believe or doubt, as you wish. I doubt.