Alibaba’s stock turnover last Wednesday, when its six-month lock-up period expired, was 34.66 million shares, more than double its average trading volume of 16.30 million shares.

It has some way to go to catch up to another US-listed tech giant, Apple, whose daily trading volume is about 50 million to 60 million shares a day, but its average daily turnover of roughly US$1.39 billion equals almost 9 per cent of Hong Kong’s main board turnover on Friday.

That shows what a loss Alibaba’s listing in New York instead of Hong Kong has been to the local stock market in terms of turnover.

It also shows why it makes sense for the city’s Securities and Futures Commission to list out the key conditions for allowing dual-share-structure listings in the future. It says it would only consider firms with founders who play vital roles and would insist on additional safeguards to ensure investor protection, such as sunset clauses stating when the privileged class of shares would expire.

Alibaba listed in the United States in September, rather than in Hong Kong, after the local exchange decided not to give it an exemption for its dual-share structure, which allows its founders and key executives to nominate a majority of the board despite the fact they hold only minority stakes.

Hong Kong bans dual-share structures while the US allows them.

After the SFC made its position clear last week, it’s not hard to imagine stock exchange staff working around the clock to draft a consultation paper for rule changes designed to encourage mainland tech firms who prefer dual-share structures to list here.

Some have cited the existence of class-action lawsuits in the US as a form of investor protection that is lacking here, but the SFC is rich and could afford to hire more investigators, allowing us to feel more comfortable about any rule changes.