The Supreme Court is currently evaluating the legality of Donald Trump's application of emergency trade authority under the 1977 International Emergency Economic Powers Act (IEEPA) to impose tariffs. This scrutiny has led to a significant decrease in prediction market probabilities favoring Trump, with Kalshi and Polymarket showing drops to 29% and 25%, respectively. Over $1.3 million has been wagered on the outcome, indicating substantial investor interest. During oral arguments, justices including Neil Gorsuch and Amy Coney Barrett expressed doubts about the executive branch's extensive use of tariff powers. Chief Justice John Roberts highlighted that tariff imposition traditionally falls under the jurisdiction of Congress, further questioning the executive's authority in this matter.