The market cares not what you think the value of an asset should be. By default, at some instant, the market is right. If you disagree, there are instruments with which you can express said disagreement and earn a profit for being correct.

By the way, the flow of Tether inbound is the flow of market participants purchasing USDT with cash equivalents. So sure, "the flow of dollars into the stock market is the only thing keeping META from its natural price of $5" is a statement anyone can make.