China's currency, the RMB, is the only major currency that is managed in a band with the USD. Other countries allow their currencies to float in the global market. But those currencies' values are determined by other central bank moves domestically, such as monetary policy that sets interest rates.

Japan is China's chief trade rival in Asia, and the Japanese central bank has for years pursued a policy of negative interest rates. They only recently pushed their borrowing rates to above zero. This artificially lowers the value of the Japanese yen, and makes Japanese exports more competitive. Even after the rate increase, the yen continues to fall versus the USD because of soaring interest rates in the US.

The high interest rates on US borrowing is now pummeling other exporters' currencies as well. The Mexican peso, the Canadian dollar, the Australian dollar, the British pound. China uniquely enjoys very high trade surpluses with the rest of the world, and in economic theory its currency should be stronger than those of almost anyone else. However, the Chinese central bank has a mandate to keep Chinese exports competitive in global markets. With other exporters' currencies in free fall and their products suddenly less expensive in US markets, China's central bank is certain to lower the RMB band in coming weeks.

Resources and links:

Bloomberg, via Yahoo! Finance, China's loosening grip on China's yuan
https://finance.yahoo.com/news/chinas...

Major currency futures: JPY, AUD, CAD, CHF, GBP; see "Futures" tab, then refer to bottom row of futures markets
https://finviz.com/futures.ashx

Bank of Japan finally ends era of negative interest rates, as BOJ pushes rates up to zero
https://www.cnbc.com/2024/03/19/bank-...
https://www.wsj.com/economy/central-b...