Online fast-fashion retailer Shein is planning to make its stock market debut in Hong Kong on August 28, marking the latest step in the Singapore-based company's long-running effort to go public, according to a person familiar with the matter, according to a report by Reuters.The company, founded in China in 2012 and now headquartered in Singapore, had previously explored listings in New York and London before turning its focus to Hong Kong.The planned IPO comes as investors assess Shein's expected valuation of around $30 billion to $40 billion, significantly below the nearly $100 billion valuation it commanded in 2022. The…