SINGAPORE — Figuring out what the Chinese central bank is doing can be as perplexing as parsing a statement by Alan Greenspan, the notoriously opaque former U.S. Federal Reserve chairman.

Now that the U.S. central bank has made it clear that any further economic assistance will have to wait until September — if it comes at all — the world relies even more on China, with the second-largest economy after that of the United States, to do what it can to support global growth.

Letting the renminbi rise more rapidly is arguably the most potent option available. It would send an immediate signal that Beijing is confident about China’s economic strength despite growing global gloom and that it is committed to a longer term goal of curbing its reliance on exports. A stronger renminbi would make Chinese exports more expensive in overseas markets.

“On any objective gauge, the Chinese currency should be higher today than it is,” Glenn Stevens, the Reserve Bank of Australia’s governor, said Friday.