JPMorgan has identified four potential outcomes following the Supreme Court's decision on tariffs. The most likely scenario, with a 66% probability, is the repeal and immediate replacement of tariffs, which could lead to a 0.75% to 1% increase in the S&P 500 index, with a 10 to 20 basis points rise by the end of the period. If tariffs are upheld, which has a 24% probability, the S&P 500 could decline by 30 to 50 basis points. A repeal and replacement after midterm elections, with a 9% chance, might boost the S&P 500 by 1.25% to 1.5%. The least likely scenario, with a 1% probability, is a repeal without replacement, potentially increasing the S&P 500 by 1.5% to 2%.