A leading Chinese brokerage house has ended market making for the mainland’s only South Korea-focused exchange-traded fund (ETF), as Beijing steps up efforts to stabilise its capital markets and protect retail investors amid volatility in its East Asian neighbour’s stock market. Shenzhen-headquartered China Merchants Securities withdrew as a liquidity provider for the Huatai-PineBridge China-Korea Semiconductor ETF barely a month after assuming the role on June 17, according to Shanghai Stock...