The following is my personal experience of how CSI is "committed" to provide accurate and clean data: In early this month I found that the CSI commodity number 119 (HSI) has several MONTHS of missing contracts between Mar 1989 to Jan 1991. I sent an email to CSI for investigation. Their answer was their database department found "no records of these contracts to have ever traded". I looked up the Hong Kong Exchange web site myself and found that the exchange themselves sell the whole database of HSI for only HK$600. I emailed CSI again and direct them to the HKEX website for the data. After several days still no action was taken. I sent another email to CSI to ask them what happened. Their answer was they will not add the missing data, without any further explanation. If you look up the CSI data for HSI, you could see a whole lot of missing data and large gaps within this period. The conclusion: CSI no longer provides clean data. Period.