The U.S. Supreme Court will make a final ruling on the legality of the tariff policy on January 9th. This decision is directly related to the direction of over hundreds of billions of dollars in tax policies and will also profoundly impact the global trade landscape and market liquidity in 2026.

Since January last year, the U.S. government has invoked the International Emergency Economic Powers Act to implement a series of tariff increases through executive orders. However, the Federal Circuit Court of Appeals and the International Trade Court have respectively ruled these policies illegal. The government then appealed to the Supreme Court, preparing for a final showdown.

In the ruling at the end of August last year, the appellate court explicitly stated that while the International Emergency Economic Powers Act allows the president to take economic measures in response to "extraordinary and special threats," this authority does not include implementing large-scale tariffs. On September 3rd, the government immediately filed an appeal with the Supreme Court, seeking to overturn this decision.

Notably, Treasury Secretary Yellen revealed a key piece of information in the submitted documents: if the Supreme Court delays the ruling until June 2026, the total tariffs currently levied could swell to between $750 billion and $1 trillion. If these tariffs are deemed illegal and require refunds, it could cause severe shocks to global markets.

The outcome of this lawsuit will not only determine the fate of these tariffs but also define the government's authority boundaries in economic policy. Whatever the result, it will bring significant changes to the trade environment and market expectations in 2026.