Stocks looked set to give up some of their gains from a stellar second quarter on Tuesday, as trade uncertainty and a flare-up in tensions between President Donald Trump and Tesla CEO Elon Musk took some steam out of the recent rally. S&P 500 futures fell 0.2%, a day after the blue-chip index locked in its best quarter since the final three months of 2023, and contracts tied to the Nasdaq 100 fell 0.3% after the tech-heavy gauge notched its own best quarterly performance in half a decade. Trump said Monday that he was preparing to send Japan a letter outlining a new tariff rate, as he accused the Asian nation of being unwilling to import American rice.