I hold a bull CBBC linked to the HSI expiring in 6 months. The spot level of the HSI increased by 0.1% since I bought the CBBC during the day. Why did the price of the CBBC remain unchanged despite an increase in the spot level of the HSI?

The price of such CBBC is based on the estimated future price of the HSI futures expiring in 6 months against which the CBBC is hedged (rather than the spot level of the HSI or the future price of the front month HSI futures). The estimated future price of the HSI is calculated by reference to the sum of the cash value of the HSI (based on the HSI’s spot level) and interest rate, less the expected dividend. Assuming all other factors remain constant, it is likely that such increase in the spot level of the HSI was offset by the adjustment of expected dividend by the issuer, and hence the price of the CBBC remained unchanged.

You may read further "I hold a very deep in-the-money call warrant linked to HSI and expiring in June (in 2 months) with entitlement ratio 10,000. The delta of the warrant is almost 1. The HSI index increased 150 points while HSI June futures contracts increased 110 points. The warrant price increased by HK$0.011 (equivalent to 110 index points) only. Why did it not increase by around HK$0.015 (equivalent to 150 index points)?" .