Foreign investors accelerated sales of Vietnamese stocks in recent weeks as trade risks grew for the export-reliant country, data shows, despite the prospect of a valuation-boosting market upgrade later this year. The Southeast Asian export hub posted a record trade surplus with the United States last year and also imposes higher duties on imports, exposing it to the risk of U.S. tariffs as the Trump administration moves to reset trade imbalances, analysts have said. Last month, foreign investors reduced their exposure to Vietnamese stocks by 6.4 trillion dong ($251.18 million), according to stock market data.