Tariff tensions will follow investors into the new year. Here’s why.

Subscribe to enjoy similar stories. This year may go into the books as one marked by trade volatility, but 2026 may not be as calm as some investors hope. Trade concerns will linger in the new year, with the Supreme Court expected to rule in early 2026 on the legality of a swath of tariffs imposed by President Donald Trump in 2025.

Cracks are also forming in some of the initial trade pacts that were announced in recent months with foreign countries. Here’s what investors need to know. The nation’s highest court will decide whether Trump’s use of the International Emergency Economic Powers Act, or IEEPA, to impose tariffs was lawful.

The Trump administration has argued that the president had the authority to impose sweeping tariffs because he declared an emergency, while a group of small businesses have argued Trump overstepped his authority in imposing the levies. Lower courts ruled that the tariffs illegal. Polymarket puts the odds of the Supreme Court striking down Trump’s IEEPA tariffs north of 70%.

Such a ruling could spark a range of questions about refunds and how the Trump administration could replace lost tariff revenue through other legal channels. A decision that strikes down IEEPA tariffs could also raise questions about the administration earlier this year suspending the de minimis exemption, which had allowed shipments under $800 into the country duty-free. The suspension hurt sales of fast-fashion giants like Shein and Temu, and created supply chain challenges for the likes of Lululemon.