On Tuesday, we weren’t surprised to learn that some banks in Shanghai and Beijing were apparently running short of physical dollar bills.

According to Ming Pao, Shanghai residents were lined up at local banks in a frantic effort to sell RMB for USD amid China’s ongoing yuan deval.

“Some banks in China’s Beijing, Shanghai and Shenzhen ran short of dollar bills for cash withdrawal amid increasing demand for the currency,” 21st Century Business Herald added, citing a reporter’s investigation which showed that “BOC, CCB, and China Merchants Bank in the listed cities are requiring an appointment at least 2 days in advance for >$5,000 purchases.” The appointment “could take as long as 1 week at some branches,” the paper said.

Why the panic? Because, in the simplest possible terms, no one has any idea what Beijing’s target is for the yuan.

In fact, no one even knows if the PBoC has a target at all or if China is simply flying by the seat of its pants managing the glidepath on an ad hoc, daily basis depending on how wide the onshore/offshore spread is (a proxy for the pressure on the currency).

One thing seems certain though: a much bigger “adjustment” will be necessary if China hopes to stabilize its economy by propping up exports. As Deutsche Bank noted last week, if global currencies continue to slide against the dollar, the yuan will need to fall if China hopes to keep its new trade-weighted RMB index from rising.

As long as the deval continues in a kind of fits and starts fashion, the capital flight will continue. That is, the only way to stabilize the situation is to allow the market to decide where the yuan should trade once and for all, a painful option in the short run, but a move that would keep the country’s capital account from dying a slow death by a thousand paper cuts. As Morgan Stanley puts it, “the capital account [currently] dominates the current account.”