Will I receive any payment if a mandatory call event occurs and how is MCE valuation period determined?

For “Category N” CBBCs, the answer is no. If a mandatory call event occurs, you will lose all of your investment.

For “Category R” CBBCs, the answer is maybe. You may receive a residual value when a Category R CBBC is being called before expiry.

For US CBBCs, please refer to here for the MCE and Residual Value calculation.

If the underlying assets are HK Stocks or Indices denominated in HKD, the residual value is calculated generally in accordance with the following principles:

(a) For a Category R “bull” CBBC – (The lowest spot price or level of the underlying asset in the MCE valuation period minus the strike price or level) divided by the entitlement ratio.

(b) For a Category R “bear” CBBC – (The strike price or level minus the highest spot price or level of the underlying asset in the MCE valuation period) divided by the entitlement ratio.

For a CBBC, MCE valuation period is a period commencing from the time upon which a mandatory call event occurs in the trading session of the Exchange up to and including the end of the following trading session.

Pre-opening session and morning session are considered as one trading session. The afternoon session and the closing auction session are considered as another trading session. In the case of half day trading, the pre-opening session, the morning session and the closing auction session are considered as one trading session. Please see the listing documents of the relevant CBBC for further details.

You may read further "For US CBBC, how to calculate the Residual Value?" .