In today's Wall Street Journal Fund Track column, Claudia Assis writes about the growing investor interest in frontier markets in developing nations. Stocks from frontier markets -- less liquid, smaller "emerging" emerging markets -- are poised to become what Assis calls "next year's darlings in emerging-market investing." In January, HSBC is planning to unveil a frontier-market fund, which will not be available in the U.S. Assis writes that other banks are seen to follow HSBC's footsteps and come out with frontier-market funds of their own offerings. Meanwhile, index provider MSCI plans to launch a frontier-market index, which will include 19 countries.