Unity Software Inc. (NYSE: U) shares fell 5.5% on October 10, 2025, in a broad market downturn sparked by renewed trade war fears between the United States and China. The decline was not linked to any specific company announcement but was part of a larger negative sentiment impacting the tech sector after President Donald Trump threatened to impose 'massive' tariffs on Chinese goods. This external macroeconomic pressure has interrupted a period of positive momentum for Unity's stock, which had seen significant gains in the preceding months.