Get 'em While They're Hot?

May Wong sat transfixed before a computer monitor, watching stock prices and anxiously awaiting her big payoff. Shares of vegetable grower China Green Holdings began trading for the first time on Jan. 13, and Wong, a 50-year-old garment importer-exporter, was one of the lucky few who had obtained shares of the hot China stock at its initial public offering (IPO) price of 16. That was no easy task, since retail investors ordered 1,604 times more shares than China Green had undertaken to sell, making it the most popular IPO in Hong Kong history. On the opening day of trading, Wong and...