Both the person acquiring and the person alienating the financial instrument are subject to HK stamp duty. The HK stamp duty is automatically withheld and DEGIRO passes this tax charge on to its clients.
In general, HK Stamp Duty is applied to transactions in shares that are listed on the Hong Kong stock exchange.
The taxable event is the purchase as well as the sell transaction.
The tax rate is 0.26% per transaction (as of 2021) and is shared equally between the buyer (0.13%) and seller (0.13%). The tax rate is calculated over the transaction value.