The Options Clearing House of HKEX will publish the settlement price file after the market closes on each trading day. You can check the settlement status of each option contract via the official link (https://www.hkex.com.hk/eng/stat/dmstat/datadownload/setdata.asp). Generally the relevant information will be published after 20:30 on the trading day;
For Hong Kong stock options, the last closing price equals the last settlement price, and the change equals the latest price minus the last trading day's closing price.
For options with trades on that day, the latest price equals the latest tick.
For options without trades on that day, the latest price equals the last settlement price.
1. Why does the option price change before the market opens and not equal last trading day's closing price (as shown on the candle chart)?
The last trading day's settlement price published by HKEX will be used as the new reference price, resulting in a price change. The candle of the last trading day will not be affected.
2. Why does the percentage change in the candle chart differ from those in the intraday chart and info panel?
The percentage changes of HK stock options in the intraday chart and info panel are calculated based on last trading day's settlement price, while the percentage change of a certain candle is based on the closing price of the last candle. Inconsistencies may thus occur.