South Korea from Monday will re-impose a ban on short-selling shares at least until June to promote a “level playing field” for retail and institutional investors, financial authorities said on Sunday. The ban was lifted in May 2021 for trades involving the shares of companies with large market capitalisation included in the KOSPI200 and KOSDAQ150 share price indices. The restriction has remained in place for most other stocks. Short-selling involves selling borrowed shares to buy back at a lower price and pocket the difference. “The measure is aimed at fundamentally easing ‘the tilted playing field’ between institutional and retail investors,” Financial Services Commission (FSC) Chairman Kim Joo-hyun told a news briefing. “Amid continued uncertainty in financial markets, major foreign investment banks have been engaged as a matter of practice in unfair trades … and we determined that it would be impossible to maintain fair trading discipline,” Kim said. The FSC will review market activity in June to decide whether there is significant improvement to allow the ban to be lifted, he said. The regulator last week said it would establish a team of investigators to probe short-selling by foreign investment banks for illegal activity including so-called naked short-selling. Naked short-selling – in which an investor short-sells shares without first borrowing them or determining they can be borrowed – is banned in South Korea.