According to the Model Code for Securities Transactions by Directors of Listed Issuers in Hong Kong Listing Rules, what must a listed issuer give the Stock Exchange before a blackout period begins?

ID : 1902

Long answer : Issuers must inform HKEX before imposing trading restrictions. (Source: https://en-rules.hkex.com.hk/sites/default/files/net_file_store/HKEX4476_3785_VER31169.pdf)

Short answer : Give the Hong Kong Stock Exchange written notice in advance.

answer 2 : Suspend all trading.

answer 3 : Issue a profit warning.

answer 4 : No requirement.