It's important to remember that behind every sale of BTC at a decreasing price is a buyer willing to purchase. Somebody is buying. The question is "why?"
As fiat currencies decline in value from inflation and, in the case of the US, from a perception (not yet embraced globally) that the US will never be able to repay its debt or service that debt except in an ever-inflated currency, Bitcoin's value will eventually increase. Why?
Because BTC 's sole function is to act as a store of value; all other currencies embrace or try to embrace a use case that drives usage. Unlike other coins, BTC's use case is its existence as an accepted store of value. Of course, that is also its limitation but gold never served more than this one function and its been used for this purpose for centuries. BTC will be the same.