Investors in some Chinese money-market funds are not only suffering smaller returns amid economic slowdown and market sluggishness, but are actually losing money, if inflation is taken into account.

The annualized rate of Yu'e Bao, the world's largest such fund with assets of some $190 billion, has fallen below 2.5% for the past two days, lower than the inflation rate for consumer goods in the past two months.

Some other funds have also seen return rates dive below 2.5%, the consumer price index reading for October and September. The profitability of money-market funds lags behind even the interest rate for two-year deposits, which average 2.6% in China.