US stock futures fell slightly Sunday evening following a ruling by the US Supreme Court that refuted the legality of a President Trump’s most sweeping tariffs, bringing new uncertainty to his key economic policy priority.

Futures tied to the Dow Jones Industrial Average (YM=F) hovered below the baseline. S&P 500 futures (ES=F) fell 0.2%, while Nasdaq 100 futures (NQ=F) slipped around 0.4%.

Markets are coming off a volatile session. On Friday, equities initially before paring gains after the Supreme Court invalidated a broad swath of Trump’s trade agenda, fueling hopes that trade tensions could ease. Still, stocks ended the day — and week — with sizable gains.

On Saturday, in response to the Supreme Court ruling, Trump said he would lift the baseline tariff rate on imports from 10% to 15%, effective immediately. It remained unclear Sunday whether Trump had formally taken steps to enact the higher duties.

Trade policy isn’t the only geopolitical concern on Wall Street. Iran remains in focus after Trump urged Tehran to reach an agreement on its nuclear program, warning of consequences if talks fail. Oil prices (BZ=F, CL=F) ended the week up more than 5%.

Meanwhile, earnings season continues to roll on, with Nvidia (NVDA) scheduled to take center stage this week when it report results Wednesday. Salesforce (CRM) also reports Wednesday for a wider view of the tech landscape, and Home Depot (HD) acts as a litmus test for retail on Tuesday.