There is a daily limit of $3.8 billion in cross-flow purchases -- with Hong Kong investors limited to 13 billion yuan ($2.1 billion) daily in A-share trades. On the program's first day, the entire quota for "north-bound" purchases of A-shares was filled by mid-afternoon, while only around 16 percent of the "south-bound" quota was used by the end of trade, according to Thomson Reuters data.
On Tuesday, the second day, the take up was slim, with around 72 percent of the north-bound quota still available by midday, while only 5 percent of the south-bound quota was used.
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Mainland investors' lack of interest in buying Hong Kong stocks is striking.
"The implication is Chinese retail investors are punters rather than long-term investors, and don't need to go to Hong Kong to do it," Julius Baer said in a note Tuesday.
Reorient's Wang also noted that many mainland investors have been able to set up Hong Kong brokerage accounts for quite some time, making the official stock connect a bit of a yawn.
Others noted that all the usual suspects are still a worry for mainland share markets.
"Just because you can does not mean you should," said Soren Aandahl, head of research at Glaucus Research. "Shanghai-listed companies have a poor record for transparency and the Shanghai stock exchange has a reputation for insider trading, lax accounting standards and subpar corporate governance."
Aandahl also cited concerns that enforcement differences could be a "flashpoint" for the two markets.
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"Hong Kong regulators have a history of clearly delineating and enforcing insider trading rules and Chinese regulators, the CSRC in particular, do not," Aandahl said. "If the playing field is not level, there's going to be an outcry and I think the program will not be unsuccessful."