Stock plunge in Hong Kong has erased 70% of company's value in past year. : Kuaishou Technology, a China video and e-commerce platform that competes with larger homegrown rival ByteDance, said on Tuesday its operating loss quadrupled in the fourth quarter of 2021 to 5.79 billion yuan, or about $904 million from 1.37 billion a year earlier amid an increase in marketing and research expenses. Covid-19 outbreak in China was adding uncertainty to the outlook, it noted.