Stock indexes surged early on Thursday after the U.S. Court of International Trade unanimously ruled that Trump didn’t have the authority to impose the sweeping tariffs.

The bombshell ruling by a little-known court will likely be appealed, but for now the tariffs have hit a roadblock.

Most of President Trump’s tariffs were halted late Wednesday by a U.S. trade court in a sharp rebuke of the president’s signature trade war policy.