The tariff loophole that drove Shein and Temu to fast-fashion dominance is closing in 8 days—and forcing the cheap brands to hike prices

China-founded e-commerce sites Temu and Shein say they plan to raise prices for U.S. customers starting next week, a ripple effect from President Donald Trump's attempts to correct the trade imbalance between the world's two largest economies by imposing a sky-high tariff on goods shipped from…