China quit selling dollars

Sort of an attempted devaluation. It was likely selling dollars, on the margin, and quit.

It may be that China government exits the dollar trade, let's the yuan float relative to dollar. That would be an action analogous to Nixon exiting the gold trade, though the dollar is not gold.  But we never know, there is no balance of powers for us to find a line of symmetry about which PBOC operates with currencies. So,their quagmire is that a true devaluation is also a devaluation of central government. It is state owned, taxes and central banking get mixed; and, thus, government is ultimately pays, one way or the other.