When Yan Jun was looking around last year for a stock market to raise capital for his Beijing-based traffic-control software company, the engineer and chairman thought he was spoiled for choice. He could sell shares of his 10-year-old company AICT on one of the three mainland exchanges – Beijing, Shanghai and Shenzhen – that together make up the world’s second-biggest capital market, with a combined value of US$10 trillion, according to Bloomberg data. Or he could raise capital offshore by...