Cash rates in China have surged to six-month highs and then eased as the central bank tries to enforce market discipline on banks to curtail unregulated lending, and there is some frustration that it seems to be introducing regular bouts of volatility.
The People's Bank of China (PBOC) wants to curb off-balance-sheet loans to sectors such as property and local governments, with authorities worried about asset-price bubbles and funds being diverted from where they are needed.
But if it sticks with using soaring rates to strong-arm banks into cutting dangerous loans, money markets could see volatility every other quarter in future, said Jim Antos, an analyst at Mizuho Securities Asia in Hong Kong.
"If this is true, it will be hugely irresponsible of the monetary authorities," he said.
The central bank says there is more than enough liquidity in the system, especially after injecting 300 billion yuan ($49 billion) last week, and that major banks need to better manage their own liquidity to match asset and liability maturities.