May Limited is listed on the Stock Exchange of Hong Kong Limited. June Limited is a company listed on the Stock Exchange of Hong Kong Limited and Shanghai Stock Exchange. In March 2020, the chief executives of these two companies, Christine and Amanda respectively, have been in secret negotiation on behalf of their companies to explore a joint venture. It is expected that these two companies would be able to earn more than HK $20 billion in this joint venture. A confidential preliminary agreement has been signed between these two companies. The formal agreement has to be confirmed by the board of directors of both companies next week.

While relaxing in her hotel bar, Amanda drank too much red wine and inadvertently mentioned the joint venture to a waitress, Mandy. Amanda said that "whoever owns shares in May Limited or June Limited will soon be happy". Although Mandy did not know Amanda, she immediately bought 20,000 May Limited shares on the Stock Exchange of Hong Kong limited and 10,000 June Limited shares on the Shanghai Stock Exchange. She made a profit substantially after the release of the joint announcement.

In addition, Christine told her mother that she could not come home for dinner for the whole week because "the board of May Limited is discussing a very substantial project". Her mother bought 10,000 May Limited's shares on the Stock Exchange of Hong Kong Limited and made a profit substantially after the release of the joint announcement.

Both May Limited and June Limited made a joint announcement about the joint venture project in early April 2020, the share prices of both companies surged substantially.

Required:

Advise Amanda, Mandy, and Christine and her mother as to whether they have any liability for insider dealing under the Securities and Futures Ordinance.