Shein shares ended their first trading week on the Hong Kong Stock Exchange 19% below the HK$48.56 offering price, reducing the fast-fashion retailer's market value from about $26 billion to roughly $21 billion. The decline was the second-worst five-session performance among Hong Kong-listed companies that raised at least $1 billion, behind Baidu Inc.'s 19.9% drop, according to Bloomberg-compiled data. Shares rose 3.2% Monday, their first gain since the IPO, after falling as much as 10% during the debut session. The weak performance reflects concerns about Shein's slowing growth, profitability, tariffs, fulfillment costs, regulatory pressure and transition toward a marketplace model. The company reported a $99 million first-quarter 2026 loss, compared with a $395 million profit a year earlier, while 2025 revenue growth slowed to 8% from 21% in 2024 and missed its target. Bloomberg Intelligence analyst Catherine Lim said company-specific concerns were the main driver, while broader skepticism toward cross-border e-commerce and stronger investor demand for artificial intelligence and robotics companies added to the pressure.