At the end of last year, few would have predicted that the Kospi, South Korea’s main stock market index, would be the best-performing major equity market this year. A short-lived attempt by the country’s then president to impose martial law, months of political turmoil and the threat of a 25 per cent tariff on South Korean exports to the United States make the Kospi’s 35 per cent gain all the more striking.There are reasons to be sceptical about the sustainability of the rally. On a cumulative...