As many hedge funds suffer from a prolonged bout of weak returns, one New York money manager says he’s found an antidote on the other side of the world. For Andrew Tsai, chief investment officer of the $750 million Chalkstream Capital Group, the answer is 6,800 miles (10,900 kilometers) away in South Korea. With the cheapest stocks in major Asian markets, a legion of day traders whipping prices around, and fewer sophisticated institutional investors to take advantage, it’s like returning to the golden era for generating alpha, or benchmark-beating performance, he says. “Quite simply, it’s an overlooked country,” Tsai,...